JP2008100901A - Carbon fibers formed from single-wall carbon nanotubes - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a large amount of continuous and macroscopic carbon fibers from single-wall carbon nanotubes at a moderate temperature using a low-priced carbon material in high yield by a single process. <P>SOLUTION: A method for purifying a mixture containing single-wall carbon nanotubes and amorphous carbon contaminants is disclosed. The method includes a process where the mixture is heated under an oxidizing condition sufficient to remove the amorphous carbon and then a product containing single-wall nanotubes of at least about 80 wt.% is recovered. A method for producing tubular carbon molecules having lengths of about 5 to 500 nm is also disclosed. The method includes a process where a mixture of tubular carbon molecules having lengths in the range of 5-500 nm is formed by cutting a material containing single-wall nanotubes and then a fraction of the molecules having substantially equal lengths is isolated. The nanotubes can be used, alone or in combination, for power transmission cables, for solar cells, for batteries, as antennas, as molecular electronics, as probes and manipulators, and for composite materials. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

Fullerenes are closed cage molecules consisting solely of sp ² hybrid carbon arranged in hexagons and pentagons. Fullerenes (eg C ₆₀ ) were first identified as closed spherical cages produced by condensation from vaporized carbon.

Fullerene tubes are produced in carbon deposits on the anode in a carbon arc process that produces spherical fullerenes from vaporized carbon. Ebbe
sen) et al [Ebbesen I], “Large-Scale Synthesis Of Carbon Nanotubes”, Nature, 358, 220 (July 16, 1992). And Ebbesen et al. [Ebbesen II], “Carbon Nanotubes”, Annual Review of Materials Science, 24, 235 (1994). Year). Such tubes are referred to herein as carbon nanotubes. Many of the carbon nanotubes produced by these methods were multi-wall nanotubes. That is, carbon nanotubes were similar to coaxial cylinders. Carbon nanotubes having up to seven layers are prior art, Ebsen II; Iijima et al., “Helical Microtubules of Graphitic Carbon”, Nature, 354, 56 (1991 11). 7th).

Single-walled carbon nanotubes were produced in a DC arc discharge device of the type used to produce fullerenes by simultaneously evaporating carbon and a small percentage of a Group VIII transition metal from the arc discharge device anode. Iijima et al., “Shingle-Shell Carbon Nanotubes of 1 nm Diameter”, Nature, 363, 603 (1993); Bethune et al., “Single Cobalt Catalyzed Growth of Carbon Nanotubes with Single Atomic Layer Walls ", Nature, 63, 605 (1993); Ajayan et al. , "Growth Morphologies During Cobalt Catalyzed Single-Shell Carbon Nanotube Synthesis, Chem. Phys. Lett., Vol. 215, p. 509 (1993); Zhou et al., “Single-Walled Carbon Nanotub Grown by Radicals from YC ₂ Particles. es Growing Radially From YC ₂ Particles ”, Appl. Phys. Lett, 65, 1593 (1994); Seraphin et al.,“ Single-walled tubes and nanocrystalline carbon. Single-Walled Tubes and Encapsulation of Nanocrystals Into Carbon Clusters, Electrochem. Soc., 142, 290 (1995); Saito et al., “Containing metals and carbides. Carbon Nanocapsules Encaging Metals and Carbides ", J. Phys. Chem. Solids, 54, 1849 (1993); and Saito et al.," Near evaporation sources. " Extrusion of Single-Wall Carbon Nanotubes Via Formation of Small Particles Condensed Near an Evaporation Source) -Time physics Let (Chem. Phys. Lett.), # 236, Volume, pp. 419 (1995). It is also known that the yield of single-walled carbon nanotubes in an arc discharge apparatus using such a transition metal mixture can be significantly increased. Lambert et al., “Improving Conditions Towards Isolating Single-Shell Carbon Nanotubes,” Chem. Phys. Lett., Vol. 226, 364. See page (1994).

  Although this arc discharge method can produce single-walled nanotubes, the yield of nanotubes is low, and the tubes exhibit notable variations in structure and size between individual tubes in the mixture. . Individual carbon nanotubes are difficult to separate and purify from other reaction products.

  An improved method for producing single-walled nanotubes is described in US patent application Ser. No. 08 / 687,665, incorporated herein by reference in its entirety, as “Ropes of Single-Walled Carbon Nanotubes. )"It is described in. This method inter alia produces single-walled carbon nanotubes in a yield of at least 50% of the condensed carbon using laser vaporization of a graphite substrate doped with a transition metal, preferably nickel, cobalt or mixtures thereof. is there. The single-walled nanotubes produced by this method consist of 10 to 1,000 single-walled carbon nanotubes arranged in parallel and closely packed in a triangular lattice by van der Waals forces. Tend to be a cluster named. Nanotubes produced by this method vary in structure, although one structure tends to dominate.

  Although the laser vaporization method yields improved single-walled nanotube formulations, the product is still heterogeneous and the nanotubes are too entangled, so many possible uses are not possible. Furthermore, carbon vaporization is a high energy process and is inherently expensive. Therefore, there remains a need for improved methods for producing single-walled carbon nanotubes with higher purity and uniformity. Furthermore, if single-walled carbon nanotubes are available as a macroscopic component, many practical materials will be able to take advantage of their physical properties. However, such ingredients have not been produced to date.

  Therefore, the object of the present invention is to produce a large amount of continuous macroscopic carbon fibers from single-wall carbon nanotubes at a moderate temperature in a single process using an inexpensive carbon raw material. Is to provide a way to do.

Another object of the present invention is to provide a macroscopic carbon fiber produced by such a method.
It is also an object of the present invention to provide a molecular arrangement of purified single-walled carbon nanotubes for use as a template in the continuous growth of macroscopic carbon fibers.

  Another object of the present invention is to provide a method for purifying single-walled carbon nanotubes from amorphous carbon and other reaction products formed by a process for producing single-walled carbon nanotubes (eg, by carbon evaporation). That is.

It is also an object of the present invention to provide a new class of tubular carbon molecules that are substantially free of amorphous carbon and optionally derivatized with one or more functional groups.
It is also an object of the present invention to provide a number of devices using the carbon fibers, nanotube molecular arrays and tubular carbon molecules of the present invention.

An object of the present invention is to provide a composite material containing carbon nanotubes.
Another object of the present invention is to provide a composite material having delamination resistance.

  A method for purifying a mixture comprising single-walled carbon nanotubes and amorphous carbon contaminants is disclosed. The method includes heating the mixture under oxidizing conditions sufficient to remove amorphous carbon, followed by recovering a product containing at least about 80 wt% single-walled carbon nanotubes.

  In another embodiment, a method for producing tubular carbon molecules of about 5 to 500 nanometers in length is disclosed. The method includes cutting a material containing single-walled carbon nanotubes to form a tubular carbon mixture having a length in the range of 5 to 500 nanometers and isolating molecular fractions of substantially equal length. Process. The disclosed nanotubes can be used alone or in multiples, for power transmission cables, solar cells, batteries, as antennas, molecular electronics, probes and manipulators, or in composites.

In another embodiment, a method for forming a macromolecular array of tubular carbon molecules is disclosed. The method substantially step of providing at least about 10 ⁶ tubular carbon molecules such lengths of the same type in the range of 50 to 500 nanometers; introducing a linking moiety to at least one end of the tubular carbon molecules, Providing a support coated with a substance to which the binding moiety adheres; and contacting the support with the tubular carbon molecules containing the binding moiety.

  In another embodiment, another method of forming a macromolecular array of tubular carbon molecules is disclosed. First, a nonascale array of microwells is prepared on a support. Next, a metal catalyst is deposited on each microwell. Next, a stream of hydrocarbon or carbon monoxide source gas is directed to the support under conditions to grow single-walled carbon nanotubes from each microwell.

  In another embodiment, yet another method for forming a macromolecular array of tubular carbon molecules is disclosed. The method comprises the steps of providing a purified but entangled surface containing relatively endless single-walled carbon nanotube material; oxidizing conditions sufficient to cause short length broken nanotubes to protrude from the surface. Applying a surface; and applying an electric field to the surface, projecting the nanotubes from the surface, aligning and aligning normally perpendicular to the surface, and aggregating them by van der Waals interaction force to form an array. Including.

In another embodiment, a method of continuously growing macroscopic carbon fibers containing at least 10 ⁶ single-walled nanotubes, generally arranged in parallel, is disclosed. The method provides a macroscopic molecular array of at least 10 ⁶ tubular carbon molecules that are generally oriented in parallel and have a substantially homogeneous length in the range of about 50 to 500 nanometers. A hemispherical fullerene cap has been removed from the upper end of the array of tubular carbon molecules. The upper end of the array of tubular carbon molecules is then contacted with the catalyst metal. In order to heat the ends of the array to a range of about 500 ° C. to 1,300 ° C., a gaseous carbon source is supplied to the ends while providing localized energy to the ends. Growing carbon fibers are continuously recovered.

In another embodiment, a macromolecular molecular array comprising at least 10 ⁶ single-walled carbon nanotubes, generally oriented in parallel and having a substantially homogeneous length in the range of about 5 to about 500 nanometers. It is disclosed.

In another embodiment, a composition containing at least about 80% by weight single-walled carbon nanotubes is disclosed.
In yet another embodiment, a macroscopic carbon fiber containing at least 10 ⁶ single-walled carbon nanotubes, generally oriented in parallel, is disclosed.

In another embodiment, an apparatus for forming continuous macroscopic carbon fibers from a macromolecular template containing at least 10 ⁶ single-walled carbon nanotubes having a catalytic metal deposited on the open end of the single-walled carbon nanotubes is disclosed. Has been. The apparatus includes means for locally heating only the open ends of the nanotubes in the template in the growth and annealing zone to a temperature in the range of about 500 ° C to 1300 ° C. The apparatus also includes means for supplying a carbon-containing source gas to a growth and annealing zone that is directly adjacent to the heated open ends of the nanotubes in the template. In addition, the apparatus also includes means for continuously removing the grown carbon fibers from the growth and annealing zone while maintaining the growth ends of the growth and annealing zone fibers.

In another embodiment, a composite material containing nanotubes is disclosed. The composite material includes a matrix and carbon nanotubes embedded in the matrix.
In another embodiment, a method for producing a composite material comprising carbon nanotube material is disclosed. The method includes the steps of providing an aggregate of fibrous materials; adding a nanotube material to the fibrous material; and adding a precursor of a matrix material to the carbon nanotube material and the fibrous material.

In another embodiment, a naturally formed three-dimensional structure of derivatized single-walled nanotube molecules is disclosed. The structure includes a number of component molecules having a number of derivatives assembled together into a three-dimensional structure.
The above objects and other objects apparent to those skilled in the art are achieved by the present invention as described in the specification and claims.

BEST MODE FOR CARRYING OUT THE INVENTION

Carbon not only has a tendency to self-assemble from hot steam to form a perfectly spherical closed cage (C ₆₀ is its prototype), but by its very nature (as a result of the transition metal catalyst) Thus, both ends tend to be a complete single-layer cylindrical tube that can be completely sealed with a half-fullerene dome. These tubes, considered as a unitary single crystal of carbon, are true fullerene molecules with no pendant bonds.

  The single-walled carbon nanotubes of the present invention appear to be much more defect-free than multi-wall carbon nanotubes. Single-walled carbon nanotubes do not have neighboring walls to compensate for defects by forming bridges between unsaturated carbon valences, but the drawbacks of single-walled carbon tubes are that multi-walled carbon nanotubes sometimes revive defects It seems that there are fewer defects than multi-walled carbon nanotubes. Single-walled carbon nanotubes are stronger and more conductive because they have few defects, and are therefore more useful than multi-walled carbon nanotubes with similar diameters.

  Carbon nanotubes, particularly the single-walled carbon nanotubes of the present invention, are used for the manufacture of electrical connectors for semiconductor devices used in microdevices such as integrated circuits or computers, because the conductivity and size of the carbon nanotubes are small. Useful. The carbon tubes are useful as optical frequency antennas as probes for scanning tunneling microscopy (STM) and scanning probe microscopy used in AFM. The carbon nanotubes may be used in place of or in combination with carbon black for automobile tires. The carbon nanotubes are also useful as support for catalysts used in industrial and chemical processes such as hydrogenation, reforming and cracking catalysts.

  The ropes made of single-walled carbon nanotubes produced according to the present invention are metallic. That is, this rope conducts electric charge with a relatively low resistance. The rope is useful for any application requiring an electrical conductor, including, for example, as an additive in conductive paints or polymer paints, or as an STM probe tip.

  When defining carbon nanotubes, it is helpful to use an accepted nomenclature system. In this specification, "Science of Fullerenes and Carbon Nanotubes" by MS Dresselhaus, G. Dresselhaus and PC Eklund. Fullerenes and Carbon Nanotubes), Chapter 19, especially pages 756-760 (1996), Academic Press, 525B Street, Chute 1900, San Diego, California 92101, US or Sea Harbor Drive, Orlando, Florida 32877, using the carbon nanotube nomenclature described in the United States (ISBN 0-12-221820-5) and included herein as a reference example. Single-layer cylindrical fullerenes are distinguished from each other by a double index (n, m). These n and m are integers describing a cutting method in which a single cylinder of hexagonal “tortoise-shaped” graphite is wound around a cylindrical surface and both ends are sealed to form a complete cylinder. When these two indices are the same (m = n), the resulting tube is a hexagonal shape in which only the sides are exposed when the tube is cut perpendicular to the tube axis. Is similar to the arm and seat of an armchair repeated n times and is said to be of the “armchair” (or n, n) type. Armchair tubes are the preferred form of single-walled carbon nanotubes because single-walled carbon nanotubes are metallic, and have very high electrical and thermal conductivity. Furthermore, all single-walled carbon nanotubes have a very high tensile strength.

  The dual laser pulse feature described here produces abundantly (10, 10) type single-walled carbon nanotubes. The (10, 10) type single-walled carbon nanotubes have an approximate tube diameter of 13.8 angstroms ± 0.3 angstroms or 13.8 angstroms ± 0.2 angstroms.

  The present invention relates to a method for producing single-walled carbon nanotubes in which a laser beam evaporates a target material containing, consisting essentially of, or consisting of carbon and one or more group VI or VIII transition metals. I will provide a. The vapor from the target is a single-walled carbon nanotube which is a main component, and among them, (10, 10) -type tubes form dominant carbon nanotubes. The method also yields significant amounts of single-walled carbon nanotubes arranged as ropes, ie, single-walled carbon nanotubes arranged in parallel to each other. The (10, 10) type tube is also the dominant tube found on each rope. This laser evaporation method has several advantages over the arc discharge method, which is a method for producing carbon tubes. In other words, the laser evaporation method makes it possible to control the conditions that help the growth of the single-walled carbon nanotubes to a much higher degree, enables continuous operation, and further improves the single-walled carbon nanotubes in a better yield. Produce quality products. As described herein, the evaporation method can also be used to produce longer carbon nanotubes and longer ropes.

  Carbon nanotubes are about 0.6 to 3 nanometers, 5 nanometers, 10 nanometers, 30 nanometers, up to 60 nanometers, and single or multi-walled carbon nanotubes for single-walled carbon nanotubes With a diameter in the range of up to 100 nanometers. The carbon nanotubes have a length in the range of 50 nanometers to 1 millimeter, 1 centimeter, 3 centimeters, 5 centimeters or more. The yield of single-walled carbon nanotubes in the product produced by the present invention is unusually high. Yields of single-walled carbon nanotubes of more than 10%, more than 30% and even more than 50% by weight of the evaporating material are possible with the present invention.

  As further described, one or more Group VI or Group VIII transition metals catalyze the growth of carbon nanotubes and / or ropes. The one or more Group VI or Group VIII transition metals also yield single-walled carbon nanotubes and single-walled carbon nanotube ropes in high yield. The mechanism by which carbon nanotube and / or rope growth is achieved is not fully understood. However, the presence of the one or more group VI or VIII transition metals at the ends of the carbon nanotubes may make it easier for the carbon from the carbon vapor to add to the solid structure forming the carbon nanotubes. The inventors believe that this mechanism is the main cause of high yield and high selectivity of carbon nanotubes and / or ropes in the product, and simply use this mechanism as a tool to explain the results of the present invention. The present invention will be described. Even if this mechanism proves to be partially or totally incorrect, the present invention that achieves these results is still fully described herein.

  One aspect of the present invention includes a method for producing carbon nanotubes and / or ropes comprising carbon nanotubes comprising supplying carbon vapor to the carbon nanotube active end while maintaining the active end of the carbon nanotube in the anneal zone. To do. Carbon is vaporized according to the present invention by a device that applies a laser beam to a target containing carbon maintained in a heated zone. Similar devices are described in the literature, eg, US Pat. No. 5,300,203 and Chai et al., “Fullerenes with Metals Inside”, incorporated herein by reference. J. Phys. Chem., No. 95, No. 20, p. 7564 (1991).

Carbon nanotubes having at least one active end are also formed when the target contains a Group VI or Group VIII transition metal or two or more Group VI or Group VIII transition metals. As used herein, the term “live end” of a carbon nanotube refers to the end of the carbon nanotube where an atom of one or more Group VI or Group VIII transition metals is located. One or both ends of the carbon nanotubes can be active ends. Carbon nanotubes with active edges are then obtained by first using a laser beam to evaporate material from the target containing carbon and one or more Group VI or Group VIII transition metals. By supplying group or group VIII transition metal vapor to the annealing zone,
Produced in the laser evaporation apparatus of the present invention. Optionally a second laser beam is used to help evaporate the carbon from the target. A carbon nanotube having an active end is formed in the annealing region, and its length grows by catalytically adding carbon in the vapor to the active end of the carbon nanotube. Additional carbon vapor is then fed to the active ends of the carbon nanotubes to increase the length of the carbon nanotubes.

  The formed carbon nanotubes are not necessarily single-walled carbon nanotubes, but multi-wall carbon nanotubes (coaxial carbon nanotubes) having any number of walls, such as two, five, or ten or more layers. A). Preferably, however, the carbon nanotubes are single-walled carbon nanotubes, and the present invention provides a method for selectively producing (10, 10) -type single-walled carbon nanotubes that are more abundant and sometimes much more abundant than multi-walled carbon nanotubes. I will provide a.

  The annealing region where the active end of the carbon nanotube is first formed is 500 ° C. to 1,500 ° C., more preferably 1,000 ° C. to 1,400 ° C., and most preferably 1,100 ° C. to 1,300 ° C. Should be maintained. In embodiments of the invention where carbon nanotubes having active ends are trapped and maintained in the anneal zone and grow length by further carbon addition (without the need for additional group VI or group VIII transition metal vapors) The annealing zone may be at a lower temperature, ie 400 ° C. to 1,500 ° C., preferably 400 ° C. to 1,200 ° C., most preferably 500 ° C. to 700 ° C. The annealing zone pressure should be maintained between 50 and 2,000 Torr, more preferably between 100 and 800 Torr, and most preferably between 300 and 600 Torr. The atmosphere in the annealing region contains carbon. Typically, the atmosphere in the anneal zone also contains a gas that cleans the carbon vapor from the anneal zone and sends it to the collection zone. Any gas that does not interfere with the formation of the carbon nanotubes acts as a cleaning gas, but preferably the cleaning gas is an inert gas such as helium, neon, argon, krypton, xenon, radon or a mixture of two or more of these gases. is there. Helium and argon are most preferred. The use of a flowing inert gas allows temperature control and, more importantly, can carry the carbon to the active end of the nanocarbon. In some embodiments of the present invention, when other materials, such as one or more Group VI or Group VIII transition metals, are vaporized with carbon, these compounds and their vapors are also present in the annealing zone atmosphere. When a pure metal is used, the resulting vapor contains that metal. When a metal oxide is used, the resulting vapor contains the metal and ions or oxygen molecules.

It is important to avoid or significantly reduce the catalytic activity of the one or more Group VI or Group VIII transition metals at the active end of the carbon nanotubes to avoid having too much material present. It is known that the presence of too much water (H ₂ O) and / or oxygen (O ₂ ) kills or significantly reduces the catalytic activity of the one or more group VI or VIII transition metals. Thus, preferably water and oxygen are excluded from the annealing zone. It is usually sufficient to use a cleaning gas having less than 5% by weight of water and oxygen, more preferably less than 1% by weight. Most preferably, water and oxygen are less than 0.1% by weight.

  Preferably, the formation of carbon nanotubes with active ends and subsequent addition of carbon vapor to the carbon nanotubes are all accomplished in the same apparatus. Preferably, the apparatus includes a laser that irradiates a target containing carbon and one or more Group VI or Group VIII transition metals, the target and annealing zone being at an appropriate temperature, for example, the annealing zone in a furnace. Maintain by holding on. The laser beam is irradiated to strike a target containing carbon and one or more Group VI and Group VIII transition metals, and the target is mounted inside a quartz tube held in a furnace maintained at an appropriate temperature. Has been. As noted above, the furnace temperature is most preferably in the range of 1,100 ° C to 1,300 ° C. The tube need not necessarily be a quartz tube, and may be made of any material that can withstand temperatures (1,000 ° C. to 1500 ° C.). In addition to quartz, alumina and tungsten could be used for making the tube.

  Improved results are obtained when the target is also irradiated with a second laser, and both lasers adjust the time, separate the times and deliver pulses of laser energy. For example, the first laser delivers a pulse intensity sufficient to evaporate material from the surface of the target. Typically, the pulse from the first laser lasts about 10 nanoseconds (ns). After stopping the first pulse, the pulse from the second laser strikes the target or the carbon vapor or plasma generated by the first pulse, causing more uniform and continuous evaporation of material from the target surface. The pulse of the second laser may be the same or weaker than the pulse of the first laser, but the pulse from the second laser is typically stronger than the pulse from the first laser. Yes, typically about 20 to 60 nanoseconds, preferably 40 to 55 nanoseconds later than the end of the first pulse.

Examples of typical specifications of the first and second lasers are shown in Examples 1 and 3, respectively. As a rough guide, the first laser can vary in wavelength from 11 to 0.1 micrometers, energy from 0.05 to 1 joule, and repetition frequency from 0.01 to 1,000 hertz (Hz). . The pulse time of the first laser can vary from 10 ^{−13 to} 10 ⁻⁶ seconds. The second laser can vary in wavelength from 11 to 0.1 micrometers, energy from 0.05 to 1 joule, and repetition rate from 0.01 to 1,000 hertz. The duration of the second laser pulse may vary between ^{10 -13} seconds to ^{10 -6} seconds. The start of the second laser pulse should be about 10 to 100 nanoseconds from the end of the first laser pulse. If the second pulse supply laser is an ultraviolet (UV) laser (eg, an excimer laser), the time delay is longer and is 1 to 10 milliseconds. However, when the second pulse is emitted from a visible or infrared (IR) laser, absorption into electrons in the plasma generated by the first pulse is preferred. In this case, the optimal time delay between pulses is about 20 to 60 nanoseconds, more preferably 40 to 55 nanoseconds, and most preferably 40 to 50 nanoseconds. These ranges for the first and second lasers are for a beam focused on a target composite rod spot of about 0.3 to 10 nanometers. The time delay between the pulses of the first and second lasers is achieved by computer control known in the field of using pulsed lasers. Inventors have included 11 Maryland Drive, Lockport, Illinois 60441, timed pulse generators and 700 manufactured by Kinetics Systems Corporation of 11 Maryland Drive, Lockport, IL 60441, USA. Chestnut Ridge Road, Chestnut Ridge Road, New York 10997-6499, Nanopulser from LeCoy Research Systems, 700 Chesnut Ridge Road, Chestnut Ridge, New York 10977-6499, USA ) And Lecoy Research Systems' CAMAC crate. Multiple first lasers and multiple second lasers are required to scale up to larger targets, or more powerful lasers are used. The main feature of multiple lasers is that the first laser ablates the material from the target surface equally to vapor or plasma, and the second laser is ablated in the vapor or plasma plume generated by the first pulse. Deposit sufficient energy on the material to ensure that the material evaporates into atoms or small molecules (less than 10 carbon atoms per molecule). If the second laser pulse arrives too early after the first pulse, the plasma generated by the first pulse is so rich that the second pulse is reflected by the plasma. When the second laser pulse arrives too late after the first pulse, the plasma and / or ablated material generated by the first pulse strikes the surface of the target. However, if the second laser pulse arrives in time just after the plasma and / or ablated material is formed, the plasma and / or ablated material will receive energy from the second laser pulse as described herein. Absorb. It should also be noted that the sequence from the first laser pulse to the second laser pulse is repeated at the same repetition frequency as the first and second laser pulses, ie, 0.01 to 1,000 hertz.

  In addition to the lasers described in the Examples, other examples of lasers useful in the present invention include XeF (wavelength 365 nanometer) laser, XeCl (wavelength 308 nanometer) laser, KrF (wavelength 248 nanometer) and ArF. A laser (wavelength 193 nanometers) is included.

  Optionally, but preferably, a cleaning gas is introduced into a tube upstream of the target, and the gas flows downstream through the target carrying vapor from the target. The quartz tube should be kept under conditions where carbon and one or more group VI or VIII transition metals are downstream of the carbon target but form carbon nanotubes in the heated portion of the quartz tube. . Collection of the carbon nanotubes generated in the annealing zone is facilitated by maintaining a cooled collector inside the downstream end of the tip of the quartz tube. For example, carbon nanotubes can be collected on a water-cooled metal structure mounted in the center of a quartz tube. Carbon nanotubes are preferably accumulated on a water-cooled collector if the conditions are appropriate.

Any Group VI or Group VIII transition metal can be used as the one or more Group VI or Group VIII transition metals of the present invention. Group VI transition metals are chromium (Cr), molybdenum (Mo) and tungsten (W). Group VIII transition metals are iron (Fe), cobalt (Co), nickel (Ni), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir) and platinum (Pt ). Preferably, the one or more Group VI or Group VIII transition metals are selected from the group consisting of iron, cobalt, ruthenium, nickel and platinum. More preferably, a mixture of cobalt and nickel or a mixture of cobalt and platinum is used. The one or more group VI or VIII transition metals useful in the present invention are used as compounds containing pure metals, metal oxides, metal carbides, metal nitrates or other group VI or VIII transition metals. be able to. Preferably, the one or more Group VI or Group VIII transition metals are used as pure metals, metal oxides or metal nitrates. The amount of the one or more Group VI or Group VIII transition metals combined with carbon to facilitate the production of carbon nanotubes with active ends is 0.1 to 10 atomic percent (atom per cent), and more Preferably it is 0.5 to 5 atomic%, and most preferably 0.5 to 1.5 atomic%. As used herein, the term “atom per cent” means a specified atomic fraction of 100 based on the total number of atoms present. For example, a 1 atomic% mixture of nickel and carbon means that 1% of the total number of nickel and carbon atoms is nickel (the remaining 99% is carbon). When a mixture of two or more Group VI or VIII transition metals is used, each metal is 1 to 99 atomic percent of the metal mixture, preferably 10 to 90 atomic percent of the metal mixture, most preferably 20 to 20 of the metal mixture. 80 atomic%. If two Group VI or Group VIII transition metals are used, each metal is most preferably 30 to 70 atomic percent of the metal mixture. When using three Group VI or Group VIII transition metals, each metal is most preferably 20-40 atomic percent of the metal mixture, as described herein, the one or more Group VI or Group VIII transition metals. Is combined with carbon to form a target for evaporation by a laser. The remainder of the target is carbon and can include carbon as a compound such as graphite-type, fullerene-type carbon, diamond-type carbon or polymers or hydrocarbons, mixtures of two or more thereof.

  Carbon is mixed with the one or more Group VI or VIII transition metals in a specific ratio and then combined in a laser evaporation method to form a target containing carbon and the one or more Group VI or VIII transition metals. . The target uniformly mixes carbon and the one or more group VI or VIII transition metals with carbon cement at room temperature, and then places the mixture in a mold. The mixture in the mold is compressed and heated at about 130 ° C. for about 4 to 5 hours. Meanwhile, the epoxy resin of the carbon cement is cured. The compression pressure used is sufficient to compress a mixture of graphite, one or more Group VI or VIII transition metals and carbon cement to form a compact without voids to maintain structural integrity. Should be. The shaped body is then carbonized by slowly heating to 810 ° C. for about 8 hours under an atmosphere of argon flow. Subsequently, the shaped and carbonized target is used for about 12 hours to about 1,200 ° C. under a stream of argon before being used as a target to generate steam containing carbon and the one or more Group VI or VIII transition metals. Heat.

  The invention will be further understood by reference to FIG. 1, which is a cross-sectional view of furnace evaporation. The target 10 is located in the tube 12. Target 10 contains carbon and may contain one or more Group VI or Group VIII transition metals. Tube 12 is located in a furnace 14 containing an insulator 16 and a heating element zone 18. The corresponding part in the furnace is indicated by the insulator 16 'and the heating element area 18'. The tube 12 is positioned such that the target 10 is in the heating element area 18.

  FIG. 1 also shows a water-cooled collector 20 mounted in the tube 12 at the downstream end 24 of the tube 12. An inert gas such as argon or helium is introduced into the upstream end 22 of the tube 12 such that the flow is from the upstream end 22 to the downstream end 24 of the tube 12. Laser beam 26 is delivered by a laser (not shown) that is focused on target 10. In operation, the furnace 14 is heated to a desired temperature, preferably 1100 ° C. to 1300 ° C., usually about 1200 ° C. Argon is introduced into the upstream end 22 as a cleaning gas. The argon may optionally be preheated to a desired temperature, ie, approximately the same as the furnace 14 temperature. The laser beam 26 hits the target 10 and evaporates the substance in the target 10. Vapor from the target 10 is carried to the downstream end 24 by a flowing argon stream. If the target consists solely of carbon, the vapor formed is carbon vapor. If one or more Group VI or VIII transition metals are included as part of the target, the vapor will contain carbon and one or more Group VI or VIII transition metals.

  Heat and flowing argon from the furnace maintain one region as an annealing zone in the tube. The volume in the tube of the portion marked 28 in FIG. 1 is the annealing zone where the carbon vapor begins to condense and then actually condenses to form carbon nanotubes. The water-cooled collector 20 collects the carbon nanotubes whose surface is maintained at a temperature of 700 ° C. or lower, preferably 500 ° C. or lower and formed in the annealing region.

  In one embodiment of the present invention, carbon nanotubes having an active end can be captured or mounted on a tungsten wire provided in the annealed region of the tube 12. In this embodiment, it is not necessary to continue producing steam having one or more Group VI or Group VIII transition metals. In this case, the target 10 can be converted into a target containing carbon but not containing a group VI or VIII transition metal, and carbon is added to the active end of the carbon nanotube.

  In another embodiment of the invention, when the target contains one or more Group VI or VIII transition metals, the vapor formed by the laser beam 26 is carbon and the one or more Group VI or VIII transitions. Contains metal. The vapor forms carbon nanotubes in the anneal zone, and the carbon nanotubes are then deposited on the water cooled collector 26, preferably at the tip 30 of the water cooled collector 26. In the presence of one or more group VI or VIII transition metals in the vapor along with carbon in the vapor, certain fullerenes and graphite usually also form, but carbon nanotubes preferentially replace fullerenes. Form. The carbon in the vapor in the annealing region is selectively added to the active end of the carbon nanotube by the catalytic effect of the one or more group VI or VIII transition metals present at the active end of the carbon nanotube.

  FIG. 2 shows an optional embodiment of the present invention that can be used to make the carbon nanotubes longer, in the annealing zone, but downstream of the target 10 and across the diameter of the tube 12 in the tungsten wire 32. Is stretched. After the pulse of the laser beam strikes the target 10 forming a carbon / VI or VIII transition metal vapor, carbon nanotubes having active edges are formed in the vapor. Some of the carbon nanotubes are trapped on the tungsten wire and the active end is directed to the downstream end 24 of the tube 12. Additional carbon vapor grows the carbon nanotubes. Carbon nanotubes with an annealing zone length of the device can be produced in this embodiment. In this embodiment, after the initial formation of the carbon nanotube having the active end portion, the vapor needs to contain only carbon at that time, so that it can be replaced with a carbon-only target.

  FIG. 2 also shows that portion of the second laser beam 34 as it strikes the target 10. Indeed, the laser beam 26 and the second laser beam 34 are directed at the same surface of the target 10, but strike the surface at different times as described herein.

  It is also possible to stop the laser or it and the second laser. Once single-walled carbon nanotubes with active edges are formed, the active edges catalyze the growth of single-walled carbon nanotubes at lower temperatures and with other carbon sources. The carbon source is switched to fullerenes and can be carried to the active end by the flow of cleaning gas. The carbon source may be graphite particles carried by a cleaning gas. The carbon source may be a hydrocarbon, hydrocarbon gas or a mixture thereof introduced into the tube 12 and carried to the active end by a cleaning gas and passing through the active end. Useful hydrocarbons include methane, ethane, propane, butane, ethylene, propylene, benzene, toluene, or other paraffinic, olefinic, cyclic or aromatic hydrocarbons, or other hydrocarbons.

  In this embodiment, the temperature of the annealing region can be lower than the temperature of the annealing region necessary for initially forming the single-walled carbon nanotube having the active end. The temperature of the annealing zone is in the range of 400 to 1,500 ° C., preferably 400 to 1,200 ° C., and most preferably 500 to 700 ° C. These low temperatures are feasible because group VI or group VIII transition metals catalyze the addition of carbon to the nanotubes at these lower temperatures.

  Measurements have shown that the single-walled carbon nanotubes in the rope have a diameter of 13.8 Å ± 0.2 Å. (10,10) type single-walled carbon nanotubes have a calculated diameter of about 13.6 angstroms, and the single-walled carbon nanotubes in the rope have been proven to be predominantly (10,10) type tubes Yes. The number of single-walled carbon nanotubes in each rope varies from about 5 to 5,000, preferably from about 10 to 1,000, or from about 50 to 1,000, most preferably from about 100 to 500. The ropes have a diameter in the range of about 20 to 200 angstroms, more preferably about 50 to 200 angstroms. In the ropes produced according to the present invention, (10, 10) single-walled carbon nanotubes occupy the main part of the tube. Ropes with more than 10%, more than 30%, more than 50%, more than 75% and even more than 90% (10, 10) type single-walled carbon nanotubes have been produced. More than 50%, more than 75%, and more than 90% armchair (n, n) single-walled carbon nanotubes are also produced according to the invention and form part of the invention. The single-walled carbon nanotubes in each rope are arranged to form a rope having a 2-D triangular lattice with a lattice constant of about 17 angstroms. Rope of 0.1 to 10 or 100 or 1,000 microns in length was produced according to the present invention. The resistivity of the ropes made according to the present invention was measured as 0.34 to 1 microohm / meter at 27 ° C., which proves that the rope is metallic.

  A felt made of the above ropes can also be produced. The product is collected in a matte form, with the entangled collection of ropes referred to herein as “felt”. The felt material collected by the inventive method has been measured to have sufficient strength to withstand handling and to be conductive. Felts of 10 millimeter square, 100 millimeter square, or 1,000 millimeter square or more are formed by the inventive method.

  One advantage of single-walled carbon nanotubes produced by in-furnace laser evaporation is its cleanliness. Single-walled carbon nanotubes produced by a typical arc discharge method are covered with a thick layer of amorphous carbon, so compared to a clean bundle of single-walled carbon nanotubes produced by laser evaporation. The usefulness is probably limited. Other advantages and features of the invention will be apparent from the disclosure. The present invention is also described by Guo et al., “Catalytic Growth Of Single-Walled Nanotubes By Laser Vaporization”, Chem. Phys. Lett. 243, 49-54 (1995).

The advantage achieved with a dual pulse laser is to ensure that the carbon and metal are subjected to optimal annealing conditions. The dual laser pulse method accomplishes this by separating the ablation from the more complete evaporation of the ablated material using time. These same optimal conditions are achieved by the use of solar energy to evaporate carbon and metals as described in US patent application Ser. No. 08 / 483,045, Jul. 7, 1995, incorporated herein by reference. The single-walled carbon nanotubes and ropes of the present application are produced by combining any Group VI or Group VIII transition metal in place of the metals described in application 08 / 483,045.
Purification of single-walled nanotubes Carbon nanotubes in materials obtained by any of the above methods can be purified according to the method of the present invention. Mixtures containing at least a portion of single-walled nanotubes (SWNT) may be made as described, for example, by Iijima et al. Or Bethune et al. However, a production method that produces single-walled carbon nanotubes in a relatively high yield is preferred. In particular, laser production methods such as those disclosed in US patent application Ser. No. 08 / 687,665 can produce up to 70% or more single-walled nanotubes, which are predominantly armchair structures. Is.

  The products of typical manufacturing processes for producing mixtures containing single-walled carbon nanotubes are amorphous carbon deposits, graphite, metal compounds (eg oxides), spherical fullerenes, catalyst particles (often carbon or fullerenes) And entangled felts, possibly including multi-walled carbon nanotubes. The single-walled carbon nanotubes are agglomerated as “ropes” or bundles of essentially parallel nanotubes.

  Purifying materials having a high proportion of single-walled carbon nanotubes as described herein, the resulting formulation is enriched in single-walled nanotubes so that the single-walled nanotubes are substantially free of other materials. In particular, single-walled nanotubes are at least 80%, preferably at least 90%, more preferably at least 95%, and most preferably more than 99% of the material in the purified formulation.

  The purification method of the present invention involves heating the single-walled nanotube-containing felt under oxidizing conditions to remove amorphous carbon deposits and other contaminants. In a preferred embodiment of the purification method, the felt is heated in an aqueous solution of an inorganic oxidizing agent such as nitric acid, a mixture of hydrogen peroxide and sulfuric acid, or potassium permanganate. Preferably, the concentration of the single-walled nanotube-containing felt is at a concentration sufficient to etch away the amorphous carbon deposits within a practical time frame, but not so high as to corrode the single-walled carbon nanotubes to a significant extent. Reflux in an oxidizing acid solution. It has been found that 2.0 to 2.6 molar nitric acid is good. Under atmospheric pressure, the reflux temperature of such an aqueous acid solution is about 120 ° C.

  In a preferred method, the nanotube-containing felt can be refluxed in a 2.6 molar nitric acid solution for 24 hours. Purified nanotubes can be recovered from the oxidized acid by, for example, filtering through a 5 micron pore size Teflon filter such as Millipore Type LS. Preferably, the filtration is followed by a second 24-hour reflux in fresh nitric acid solution of the same concentration.

  When refluxing under acidic oxidation conditions, some of the nanotubes will result in an esterification reaction, in other words, nanotube contamination. This contaminating ester material can be removed by saponification, for example by using saturated sodium hydroxide solution in room temperature ethanol. Other conditions suitable for saponification of any ester linked polymer produced by the oxidative acid treatment will be readily apparent to those skilled in the art. Typically, the nanotube formulation is neutralized after the saponification step. While refluxing the nanotubes for 12 hours in a 6 molar aqueous hydrochloric acid solution has been found suitable for neutralization, other suitable conditions will be apparent to those skilled in the art.

After oxidation and optional saponification and neutralization, the purified nanotubes are formed by precipitation or filtration into a thin mat of purified fibers consisting of ropes or bundles of single-walled nanotubes, hereinafter referred to as “bucky paper”. Can be recovered. In a typical example, the purified neutralized nanotubes were filtered with a Teflon membrane having a 5 micron pore size to obtain a black mat of purified nanotubes about 100 microns thick. “Buckypaper” nanotubes can be of various lengths, consisting of individual nanotubes or bundles or ropes of up to 10 ³ single-walled nanotubes, or a mixture of individual single-walled nanotubes and ropes of various thicknesses. Yes. Alternatively, “bucky paper” may consist of nanotubes of uniform length or diameter and / or molecular structure by fractionation as described below.

  The purified nanotubes or “bucky paper” are finally dried, for example, by baking and solid baking in a hydrogen gas atmosphere at 850 ° C. to yield a dry purified nanotube formulation.

  The laser-produced single-walled nanotube material produced by the dual laser method of US patent application Ser. No. 08 / 687,665 was refluxed once in a 2.6 molar aqueous nitric acid solution with solvent exchange and then in ethanol. In saturated sodium hydroxide at room temperature for 12 hours, neutralized with a 6 molar aqueous hydrochloric acid solution for 12 hours, the aqueous medium was removed, and 1 atmosphere under a hydrogen gas atmosphere at 850 ° C. When baked in hydrogen gas (flow rate 1 to 10 centimeters / second in a 1-inch quartz tube) for 2 hours, as a result of detailed TEM, SEM and Raman spectroscopic analysis, the purity exceeded 99%. The main impurities were few carbon encapsulated nickel / cobalt particles. (See FIGS. 3A, 3B and 3C).

  In another embodiment, slightly basic solutions (eg, pH of about 8 to 12) can be used in the saponification step. Initial washing in 2.6 molar nitric acid converts the amorphous carbon in the crude material to fulvic acid as well as larger polycyclic aromatic hydrocarbons with various functional groups, especially carboxylic acid groups at the periphery. And conjugated polycyclic compounds of various sizes such as humic acid. The base solution ionizes most polycyclic compounds and facilitates dissolution in aqueous solutions. In a preferred method, the nanotube-containing felt is refluxed at about 110 ° C. to 125 ° C. for 6 to 15 hours in 2 to 5 molar nitric acid. The purified nanotubes are filtered and washed with 10 mM sodium hydroxide solution on a TSTP Isopore filter with a 3 micron pore size. The filtered nanotubes were then polished by stirring in a sulfuric acid / nitric acid solution at 60 ° C. for 30 minutes. In a preferred embodiment, the solution is a 3: 1 volume ratio of concentrated sulfuric acid and nitric acid. In this step, all residual material produced during the nitric acid treatment is essentially removed from the tubes.

  When polishing is complete, dilute 4 times with water and filter the nanotubes again over a 3 micron pore size TSTP Isopore filter. The nanotubes are again washed with 10 mM sodium hydroxide solution. Finally, the nanotubes are stored in water because it is difficult to resuspend once the nanotubes are dry.

Although the conditions can be further optimized for special applications, this basic approach by refluxing in oxidizing acid has been shown to be successful. Purification of the process yields single-walled nanotubes for catalysts, composite components, or starting materials in the production of continuous macroscopic carbon fibers of cylindrical and single-walled nanotube molecules.
Single-walled carbon nanotube molecules Single-walled nanotubes produced by prior art methods are so long and tangled that they are very difficult to purify or manipulate. However, the present invention provides for cutting the single-walled nanotubes to a length that is no longer entangled and annealing to close the open end. Short closed cylindrical carbon nanotubes can be very easily purified using techniques similar to those used for DNA segmentation or sorting by polymer size. Thus, the present invention effectively provides a truly new class of cylindrical carbon nanotubes.

  Preparation of a uniform collection of short carbon nanotubes is achieved by cutting the nanotubes, annealing (resealing), and subsequent fractionation. The cutting and annealing steps are performed on purified nanotube “bucky paper”, felt prior to nanotube purification, or any material containing single-walled nanotubes. When cutting and annealing is performed on the felt, it is preferably performed following oxidative purification and optional saponification to remove amorphous carbon. Preferably, the starting material for the cutting step is a purified single-walled nanotube that is substantially free of other materials.

  Short nanotubes can be cut either to a certain length that facilitates their intended use, or to select a range of lengths. For applications involving individual cylindrical molecules themselves (eg, derivatives, nanoscale conductors in quantum devices, ie molecular interconnects), the length is exactly greater than the tube diameter, approximately 1,000 times the tube diameter. Up to twice. Typical cylindrical molecules range from about 5 to 1,000 nanometers or longer. As described below, a length of about 50 to 500 nanometers is preferred to create a template useful for the growth of single-walled nanotube carbon fibers.

  Any cutting method that achieves the desired nanotube molecular length without substantially affecting the structure of the remaining fragments can be employed. A preferred cutting method employs irradiation of high mass ions. In this method, a sample is irradiated with a fast ion beam from, for example, a cyclotron with an energy of about 0.1 to 10 gigavolts. Preferred high mass ions include those greater than about 150 atomic mass units, such as bismuth, gold, uranium.

Preferably, the preparation of a population of individual single-walled nanotubes having a uniform length starts with a non-uniform “bucky paper”, and the nanotubes in the “paper” use a gold (Au ⁺³³ ) fast ion beam And cut. In this exemplary procedure, a “bucky paper” (thickness of about 100 microns) is irradiated with up to about 10 ¹² fast ions / centimeter square, and every 100 nanometers along the length of the nanotube, “paper” It causes severe damage to the nanotubes inside. Fast ions create damage to the “bucky paper” in a manner similar to a “bullet through hole” of 10 to 100 nanometers penetrating the sample. The damaged nanotubes can then be annealed (closed) by hot sealing of the tube at the point where ion damage has occurred, yielding a number of shorter nanotubes. The shorter cylindrical molecules produced at the level of these bundles have an irregular cut size distribution with a peak around length of about 100 nanometers. Appropriate annealing conditions are well known in the fullerene art, such as baking tubes in a vacuum or inert gas at 1200 ° C. for 1 hour. By including defect biogenic atoms in the structure, it can be cut into shorter cylindrical molecules. These defects can be created chemically (eg, by oxidative attack) to cut the nanotubes into smaller cuts. For example, single-walled nanotubes with visceral weakness against chemical attack can be produced by including one boron per 1000 carbon atoms in the initial carbon evaporation source.

  Cutting can also be accomplished by ultrasonically decomposing a single-walled nanotube suspension in a suitable medium, such as a liquid or molten hydrocarbon. Any device that produces suitable acoustic energy can be used. One preferred liquid of this type is 1,2-dichloroethane. One device of this type is the Compact Cleaner (One Pint) manufactured by Cole-Parmer, Inc. This type operates at 40 kilohertz and has an output of 20 watts. The sonication cutting method should be performed continuously with sufficient energy input and for a time sufficient to substantially reduce the length of the tube, rope or cable present in the initial suspension. Typically from about 10 minutes to about 24 hours are used depending on the nature of the starting material and the desired length reduction.

  In another embodiment, the rope is caused by high temperature and pressure created by bubble collapse (less than 5,000 ° C. and less than about 1,000 atm) or by free radical attack produced by ultrasonic chemistry. Sonication can be used to generate defects along the length. These defects are attacked by the sulfuric acid / nitric acid solution, cutting the nanotubes cleanly and exposing the underlying damage and cutting tube. When the acid attacks the tube, the tube is completely cut open and gradually begins to erode and the open end cannot be closed again at a mild temperature. In a preferred method, the nanotubes are bath sonicated while stirring in a sulfuric acid / nitric acid solution at 40-45 ° C. for 24 hours. It is then stirred in the sulfuric acid / nitric acid solution at 40-45 ° C. for 2 hours without sonication. This attacks all defects generated by ultrasonic decomposition with the sulfuric acid / nitric acid solution without generating any further defects. The nanotubes are then diluted 4 fold with water and filtered using a 0.1 micron pore size buoy tee (VCTP) filter. The nanotubes are then filtered and washed with 10 mM sodium hydroxide solution on the VCTP filter. The nanotubes are polished by stirring for 30 minutes at 70 ° C. in a sulfuric acid / nitric acid solution. The polished nanotubes are diluted 4 times with water, filtered using a 0.1 micron pore size VCTP filter, then filtered and washed with 10 millimolar sodium hydroxide on a 0.1 micron pore size VCTP filter. Store in water.

  For example, oxidative corrosion methods using high concentrations of nitric acid can also be used to cut single-walled nanotubes to shorter lengths. For example, refluxing single-walled nanotubes in concentrated nitric acid for several hours to one or two days results in significantly shorter single-walled nanotubes. The cutting speed by this mechanism depends on the helicity of the tube. By utilizing this fact, it becomes easy to separate the tube of the (n, n) type from the (n, m) type.

The length distribution is systematically shortened according to the exposure time to the acid. For example, the average cleavage of nanotubes at 70 ° C. in a concentrated sulfuric acid / nitric acid solution with a volume ratio of 3 to 1 is shortened at a rate of about 100 nanometers / hour. At 70 ° C. in a 4: 1 volume ratio sulfuric acid / 30% aqueous hydrogen peroxide (“piranha”) mixture, the shortening rate is approximately 200 nanometers / hour. The rate of corrosion is the chiral index (n, m) of the nanotube, ie all arm-chair tubes (m = x) that are chemically distinct from zigzag tubes (m = o). It is very sensitive to nanotubes with intermediate helical angles (n ¹ m).

By this step, the cleaned nanotube is cut to a length of 50 to 500 nanometers, preferably 100 to 300 nanometers. The resulting fragment Triton X ^{-100 (Triton X-100 a)} [ Aldrich, Milwaukee, Wisconsin, United States United States (Aldrich, Milwaukee, WI, USA )] is mixed with a surfactant such as, water colloidal suspension Form a liquid. This black suspension can be subjected to various operations such as length sorting using electric field flow fractionation and electrodeposition onto graphite followed by AFM imaging.

In another embodiment, single-walled nanotubes can be cut in a known manner using an electron beam cutting device.
A combination of the above cutting techniques can also be used.

  A uniform population of single-walled nanotubes can be prepared by fractionating the heterogeneous nanotube population after annealing. The annealed nanotubes can be dispersed in an aqueous detergent solution or organic solvent for fractionation. Preferably, the tube is dispersed by sonication in benzene, toluene, xylene or molten naphthalene. The main function of this procedure is to separate the nanotubes bound in ropes or mats by van der Waals forces. Following separation into individual nanotubes, the nanotubes can be sorted by size using known fractionation procedures such as DNA fractionation or polymer fractionation procedures. Separation can also be performed on the tube before annealing, particularly when the open end has a substituent (carboxy group, hydroxyl group, etc.), and separation by either size or type is facilitated. Alternatively, the closed tube can be opened and such substituents introduced as derivatives. A closed tube can also be derivatized to facilitate fractionation, for example, by adding a soluble portion to the end cap.

  Electrophoresis is one such technique and is more suitable for fractionation because single-walled nanotube molecules are easily negatively charged. It is also possible to separate nanotubes by type using different polarization and electrical properties of single-walled nanotubes with different structural types (eg armchair type and zigzag type). Separation by type can also be facilitated by derivatizing the mixture of molecules with a moiety that binds preferentially over one type of structure.

In a representative example, a 100 micron thick mat of black “bucky paper” consisting of nanotubes purified by refluxing in nitric acid for 48 hours on the Texas A & M Superconducting Cyclotron Facility. A 2 g electron volt beam of gold (Au ⁺³³ ) ions (up to 10 ¹² ions / centimeter square net flux) was irradiated for 100 minutes. The irradiated “paper” was baked in vacuum at 1,200 ° C. for 1 hour, the tube was sealed with “bullet through-holes”, and then dispersed in toluene while ultrasonically. The obtained cylindrical molecules were examined by SEM, AFM and TEM.

  Single-walled nanotubes in which the cylindrical portion is formed from a substantially defect-free sheet of graphene [graphene (hexagonal bonded carbon)] rolled and bonded at both ends parallel to the long axis by the procedure described herein A cylindrical molecule is produced. The nanotubes can have a fullerene cap (eg, hemispherical) at one end of the cylinder and a similar fullerene cap at the other end. One or both ends may also be open. These single-walled nanotubes prepared by the methods described herein are substantially free of amorphous carbon. These purified nanotubes are indeed a truly new class of cylindrical molecules.

In general, the length, diameter, and helicity of these molecules can be controlled to any desired value. The preferred length is up to 10 ⁶ hexagons, the preferred diameter is about 5 to 50 hexagonal perimeter, and the preferred helix angle is 0 to 30 degrees.

Preferably, the cylindrical molecule is produced by cutting and annealing nanotubes consisting of a main armchair (n, n) configuration obtained by purifying the material produced by the methods discussed above. These (n, n) type carbon molecules, when purified as described herein, are the first true “metallic molecules”. These molecules are useful in the manufacture of electrical connectors for devices such as integrated circuits and semiconductor chips used in computers because carbon molecules are highly conductive and small in size. Single-walled nanotube molecules are also useful as components in electrical devices where quantum effects dominate at room temperature, such as, for example, resonant tunneling diodes. The metallic carbon molecules are useful as optical frequency antennas and as deep needles in scanning probe microscopy as used in STM and AFM. Semiconductor single-walled nanotube structures in the case of (m, n) -type tubes with m ¹ n can be used as nanoscale semiconductor devices, such as transistors, when properly doped.

The cylindrical carbon molecules of the present invention can also be used, for example, in high frequency shielding applications for making microwave absorbing materials.
Single-walled nanotube molecules can serve as catalysts with the additional advantages that the linear arrangement of the molecules provides in any reaction known to be catalyzed as fullerenes. Carbon nanotubes are also useful as support for catalysts used in industrial and chemical processes such as hydrogenation, reforming and cracking catalysts. Materials comprising single-walled nanotube molecules are also useful as hydrogen storage devices for batteries and fuel cells.

  Cylindrical carbon molecules produced in accordance with the present invention can be chemically derivatized at their ends that are open or sealed with a hemi-fullerene dome. Derivatization of fullerene cap structures is facilitated by the known reactivity of the structure. “The Chemistry of Fullerenes”, edited by R. Taylor, Volume 4 of the Advance Series in Fullerenes, World Science Publishers, Singapore ( (1995) and A. Hirsch, "The Chemistry of the Fullerenes", Thieme (1994). Alternatively, fullerene caps for single-walled nanotubes can be obtained by briefly exposing them to oxidizing conditions (eg nitric acid or oxygen / carbon monoxide) that are sufficient to open the tube but do not erode too much back. It can be removed at both ends and the end of the resulting open tube can be derivatized using known reaction mechanisms for reactive sites at the end of the graphene sheet.

  In general, the structure of such a molecule is shown as follows:

In this structure

Has about 10 ^{2 to} about 10 ⁶ carbon atoms and has a length of about 5 to 1,000 nanometers, preferably about 5 to 500 nanometers (optionally doped with non-carbon atoms). A cylindrical graphene sheet substantially free of defects;

Fully fits into the cylindrical graphene sheet and has at least 5 pentagons and the remainder hexagon, typically having at least about 30 carbon atoms;
n is 0 to 30, preferably 0 to 12; and
R, R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently hydrogen; alkyl, acyl, aryl, aralkyl, halogen; substituted or unsubstituted thiol; substituted or unsubstituted amino; hydroxyl and OR '(Wherein R is hydrogen, alkyl, acyl, aryl, aralkyl, substituted or unsubstituted amino; substituted or unsubstituted thiol; halogen; and optionally interrupted by one or more heteroatoms or optionally Selected from the group consisting of one or more = O or = S, selected from the group consisting of hydroxyl, aminoalkyl groups, amino acids or linear or cyclic carbon chains substituted with peptides of 2 to 8 amino acids) Is done.

The following definitions are used in the specification and claims.
The term “alkyl” as used herein and in the claims (hereinafter “herein”) includes both linear and branched chain groups such as methyl, ethyl, propyl, isopropyl, Butyl, tertiary butyl, isobutyl, pentyl, hexyl, isohexyl, heptyl, 4,4-dimethylpentyl, octyl, 2,2,4-trimethylpentyl, nonyl, decyl, undecyl, dodecyl and various branched chains thereof Including isomeric isomers. The chain may be linear or cyclic, saturated or unsaturated, and may contain, for example, double and triple bonds. The alkyl group may be interrupted or substituted with, for example, halogen, oxygen, silyl, amino or other acceptable substituents.

  As used herein, the term “acyl” refers to the formula —COR where R is any substituent, eg, alkyl, aryl, aralkyl, halogen; substituted or unsubstituted thiol; substituted or unsubstituted amino, Substituted or unsubstituted oxygen, hydroxy or hydrogen).

  The term “aryl” as used herein refers to a monocyclic, bicyclic or tricyclic aromatic group containing 6 to 14 carbon atoms in the ring portion, for example phenyl, naphthyl, substituted phenyl or substituted naphthyl. And the substituent of phenyl or naphthyl is, for example, an alkyl group having 1 to 4 carbon atoms, halogen, alkoxy having 1 to 4 carbon atoms, hydroxy or nitro.

  The term “aralkyl” as used herein refers to the above alkyl groups having an aryl substituent such as benzyl, paranitrobenzyl, phenylethyl, diphenylmethyl and triphenylmethyl.

As used herein, the term “aromatic or non-aromatic ring” refers to an aromatic or non-aromatic 5- to 8-membered ring that is interrupted or uninterrupted by one or more heteroatoms such as O, S, SO ₂ and N. The ring may contain or be substituted with, for example, halogen, alkyl, acyl, hydroxyl, aryl and amino, and the heteroatom and substituent may also be, for example, alkyl, acyl, aryl or It may be substituted with aralkyl.

  The term “linear or cyclic” as used herein includes, for example, more linear chains, optionally interrupted by aromatic or non-aromatic rings. Cyclic chains include, for example, aromatic or non-aromatic rings that may be attached to carbons that precede or follow the ring.

  The term “substituted amino” as used herein refers to an amino group that may be substituted with one or more substituents such as alkyl, acyl, aryl, aralkyl, hydroxy, and hydrogen.

  The term “substituted thiol” as used herein refers to a thiol that may be substituted with one or more substituents such as alkyl, acyl, aryl, aralkyl, hydroxy, and hydrogen.

  Typically, the open end can contain up to about 20 substituents and the closed end can contain up to about 30 substituents. Due to steric hindrance, it is preferred to use up to about 12 substituents per end.

In addition to the above external derivatization, the single-walled nanotube molecules of the present invention can be modified by inclusion, ie, by including one or more metal atoms in the structure, as is known in the endohedral fullerene art. it can. One or more smaller molecules that do not bind to the structure, eg, C ₆₀ , are “loaded” into the single-walled nanotube molecule, and the C ₆₀ “buckyball ( It is also possible to switch molecules without the bucky ball) moving back and forth frequently.

To produce encapsulated cylindrical carbon nanotubes, internal species (eg, metal atoms or “buckyball” molecules) can be introduced during the single-wall nanotube formation process or added after the cylindrical molecules are prepared. . Incorporation of metals into the carbon source that is evaporated to form single-walled nanotube material is accomplished by the methods described in the prior art for producing encapsulated metal fullerenes. “Buckyballs”, or spherical fullerene molecules, remove the cap at one or both ends of the tube using the oxidative erosion technique described above and leave the mixture in the presence of steam containing C ₆₀ or C ₇₀ ( Loading into the cylindrical carbon molecules of the present invention by adding an excess of “buckyball” molecules (eg, C ₆₀ or C ₇₀ ) by heating for an equilibration time (eg, from about 500 ° C. to about 700 ° C.). It is preferable. A significant percentage of tubes (eg, a few tenths of 1% to about 50% or more) captures “buckyball” molecules during the process. Selecting the relative placement of the tube and “ball” can make the method easier. For example, C ₆₀ and C ₇₀ fit very well into cylindrical carbon molecules cut from (10, 10) type single-walled nanotubes (inner diameter about 1 nanometer). After the loading process, the tube containing the “buckyball” molecules is closed by heating at about 1,000 ° C. under vacuum (closed by annealing). Encapsulation of “bucky balls” can be confirmed by microscopic inspection, for example, TEM.

  Incorporated cylindrical carbon molecules are then introduced into new physical properties introduced into the loaded cylindrical molecules from empty tubes and any remaining loaded material, e.g. metal atoms become magnetic or paramagnetic. When it is applied to the tube, or when the “bucky ball” imparts an excessive mass to the tube, it can be separated using its physical properties. Separation and purification based on these and other physical properties will be readily apparent to those skilled in the art.

Fullerene molecules such as C ₆₀ or C ₇₀ were selected appropriately to give the environment a more stable energy configuration than obtained outside the tube from an electronic point of view (eg, via van der Waals interactions) Remain inside cylindrical molecules [eg, those based on (10, 10) single-walled nanotubes].
Molecular arrangement of single- walled carbon nanotubes One particularly interesting application for a uniform population of single-walled nanotube molecules is the orientation in a substantially equilibrium to form a single-wall that extends in a direction substantially perpendicular to the individual nanotube orientation. To produce a substantially two-dimensional array of single-walled nanotubes that condense (eg, due to van der Waals forces). Such monolayer arrangements are described in “Self-assembled monolayers (SAM)” or “Langmuir-Blodgett films” (Hirsch, p. 75). To page 76]]. Such a single layer arrangement is shown schematically in FIG. In this figure, the nanotubes 1 are bound to a substrate 2 having a reactive coating 3 (eg gold).

Typically, self-assembled monolayers are created on a substrate that is a metal [such as gold, mercury or ITO (indium-tin-oxide)]. The molecules that are of interest, but here is a single-walled nanotube molecules _{in, -S-, -S- (CH 2)} n-NH-, -SiO 3 (CH 2) 3 NH- or the like linkers (linker ) Through the moiety (usually covalently) to the substrate. The binding moiety first binds to the substrate or first to the single-walled nanotube molecule (the open or closed end) to provide reactive self-assembly. The LB film is formed at the interface between a two-phase hydrocarbon (such as benzene and toluene) and water. Orientation of the membrane is achieved by using molecules or linkers having hydrophilic and lipophilic portions at opposite ends, respectively.

  The arrangement of the array of single-walled nanotube molecules can be uniform or non-uniform depending on the application served. Using single-walled nanotube molecules of the same type and structure, a uniform arrangement of the kind shown in FIG. 4 is obtained. Using different single-walled nanotube molecules yields random or ordered heterogeneous structures. An example of the irregular order arrangement is shown in FIG. Here, the tube 4 is (n, n) -type, i.e. metallic in structure, and the tube 5 is (m, n) -type, i.e. insulative. This arrangement is achieved by using a sequential reaction after removing the previously masked regions of reactive substrate.

Arrays comprising 10 ^{3 to} 10 ¹⁰ or more single-walled nanotube molecules in a substantially parallel relationship are themselves used as nanoporous conductive molecular films, for example, in batteries such as lithium ion batteries. Can do. This film is also (with or without the addition of photoactive molecules such as cis- [bisthiocyanatobis (4,4′-dicarboxy-2,2′-bipyridine Ru (II))]) It can be used to produce a highly efficient lightning cell of the type shown in US Pat. No. 5,084,365.

  One preferred use of the single-walled nanotube molecular array of the present invention is to provide a “seed” or template for the growth of macroscopic carbon fibers of single-walled carbon nanotubes as described below. The use of a macroscopic cross section in this mold is particularly useful to keep the active (open) ends of the nanotubes exposed to the raw material during fiber growth. The template sequences of the present invention can be used as formed on the initial template, or separated from the initial template, or without a substrate (because of the van der Waals forces), and the fibers It can also be used by transferring to a second substrate more suitable for the conditions of formation.

  If the single-walled nanotube molecular array is used as a seed or template for growing macroscopic carbon fibers as described below, the array need not be formed as a substantially two-dimensional array. Any arrangement that provides a two-dimensional arrangement on the surface above it can be used. In its preferred embodiment, the template molecule sequence is a macroscopic carbon of a length that can be manipulated as produced below.

  Any method of forming a preferred template molecule sequence involves using purified “bucky paper” as the starting material. Oxidizing the surface of a “bucky paper” (eg, at about 500 ° C. with oxygen / carbon monoxide) attacks the sides as well as the ends of single-walled nanotubes, and many tubes and / or rope ends Projects from the surface of the "paper". When the resulting “bucky paper” is placed in an electric field (eg, 100 volts / centimeter square), the protruding tubes and / or ropes are arranged in a direction substantially perpendicular to the “paper” surface. These tubes tend to aggregate and form molecular arrays due to van der Waals forces.

  Alternatively, molecular arrays of single-walled nanotubes can be produced by “combing” purified “bucky paper” starting materials. “Spinning” involves arranging nanotubes using a sharp macroscopic tip such as a silicon pyramid on a cantilever of a scanning force microscope (SFM). Specifically, “spinning” is a process in which the tip of the SFM is systematically plunged into “bucky paper”, dragged, and pulled up from “bucky paper”. The whole piece of “Bucky Paper”, for example, (1) systematically pushes the tip of the SFM into the piece of “Bucky Paper”, drags and advances along it, (2) until one row is completed (1) The event can be repeated by repeating the events and (3) repositioning the tip along another row and repeating (1) and (2). In a preferred turning method, a piece of “bucky paper” of interest is subjected to the above steps (1) to (3) at a certain depth and then repeated at all other depths. The insult is complete. For example, a 10 micrometer square “bucky paper” is written with a lithographic action plan that can draw 20 lines at intervals of 0.5 micrometer and thus implement it. This action plan can be implemented seven times from zero to 3 microns with increasing depth by 0.5 microns.

Large arrays (i.e., more than 10 < ⁶ > nanotubes) can be obtained by combining smaller arrays into one, or by folding a linear collection of tubes and / or ropes (i.e., once a collection of n tubes is folded, 2n Assemble using nanoprobes (in bundles of tubes).

Macroscopic arrays can also be microwell (microwell) structure nanoscale (e.g., width 10 nm formed on the surface by electron-beam lithography technique, depression rectangle above ¹⁰⁶ depth 10 nanometers [wells ( It can also be formed by providing a silicon dioxide-coated silicon wafer) having well)]. Preferably, catalytic metal clusters (or precursors) are deposited in each well and the carbon-containing source is directed to the array under the conditions described below to initiate growth of single-walled nanotube fibers from the well. Pre-formed nanoparticles (ie, “Dai et al.“ Single-Wall Nanotubes Produced by Metal Catalyzed Disproportionation of Carbon Monoxide ””). , Chem. Phys. Lett. Vol. 260 (1996), pp. 471 to 475 (hereinafter referred to as “die”) having a diameter of several nanometers] These catalysts can also be used in the wells. An electric field can be applied to orient the fibers in a direction substantially perpendicular to the wafer surface.
Growth of continuous carbon fibers from single-walled nanotube molecular arrays The present invention provides a method for growing continuous carbon fibers from single-walled nanotube molecular arrays to any desired length. Carbon fibers containing aggregates of substantially parallel carbon nanotubes can be produced according to the method of the present invention by growth (elongation) of a suitable seed molecular array. Preferred single-walled nanotube molecular arrays are produced as described above from self-assembled single-walled single-walled nanotubes of substantially uniform length. As used herein, the term “macroscopic carbon fiber” refers to a diameter large enough to be physically manipulated, typically greater than about 1 micron, and preferably greater than about 10 microns. The fiber which has.

  The first step in the growth method is to open the growth end of the single-walled nanotube in the molecular arrangement. This is achieved by an oxidation treatment as described above. The transition metal catalyst is then added to the open end seed array. The transition metal catalyst is any transition metal that converts the following carbon-containing feedstock into a highly mobile carbon free radical that can be transferred to the preferred hexagonal structure at the growth end. Preferred materials include transition metals, particularly group VI or group VIII transition metals, ie chromium (Cr), molybdenum (Mo), tungsten (W), iron (Fe), cobalt (Co), nickel (Ni), Ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), and platinum (Pt) are included. Lanthanoid and actinide metals can also be used. Preference is given to iron, nickel, cobalt and mixtures thereof. Most preferred is a 50/50 ratio (weight) mixture of nickel and cobalt.

  The catalyst should be present at the end of the single-walled nanotube open as a metal cluster containing about 10 to about 200 metal atoms (depending on the diameter of the single-walled nanotube molecule). Typically, the reaction proceeds most efficiently when the catalytic metal cluster sits on top of an open tube and does not cross over one or more tubes. More preferred are metal clusters having a cross section equal to about 0.5 to about 1.0 times the diameter of the tube (eg, 0.5 to about 1.5 nanometers).

In the preferred method, the catalyst is formed in situ on the end of the open tube of molecular alignment by vacuum deposition. Any preferred apparatus is used such as those used in molecular beam epitaxy (MBE) deposition. One such device is the Kudsen Effusion Source Evaporator. A wire (eg, nickel / carbon monoxide wire or separate wires of nickel and carbon monoxide) near the end of the tube at a temperature below the melting point at which enough atoms evaporate from the surface of the wire (eg, about It is also possible to sufficiently deposit the metal by simply heating to 900 ° C. to 1,300 ° C.). The vapor deposition is preferably carried out in advance by outgassing in a vacuum. A vacuum of about 10 ⁻⁶ torr to 10 ⁻⁸ torr is suitable. The evaporation temperature should be high enough to evaporate the metal catalyst. Typically, temperatures in the range of 1500 ° C. to 2,000 ° C. are suitable for the preferred embodiment nickel / carbon monoxide catalyst. In the evaporation method, the metal is typically deposited as a single layer of metal atoms. About 1 to 10 monolayers is generally the required amount of catalyst. The deposition of transition metal clusters on the open tube apexes can also be performed by laser evaporation of the metal target in the catalyst deposition zone.

  The actual catalyst cluster formation at the open tube end is high enough to provide sufficient species movement so that the tube end can locate and cluster the open end of the metal atom into a cluster. This is done by heating to a temperature that is not high enough to close the end of the tube. Typically, temperatures up to about 500 ° C. are suitable. For one preferred embodiment, the nickel / carbon monoxide catalyst system, a temperature in the range of about 400 ° C to 500 ° C is preferred.

  In a preferred embodiment, the catalytic metal clusters are deposited on the open nanotubes by a docking process that ensures the best place for the subsequent growth reaction. In this method, metal atoms are supplied as described above, but the conditions are modified to provide reducing conditions, eg, 1 to 10 minutes at 800 ° C. and 10 millitorr of hydrogen. These conditions are such that metal atom clusters move through the system in search of reaction sites. During the reduction heating, the catalyst material eventually finds the open end and settles there, and begins to etch back the tube. The reduction time should be long enough for the catalyst particles to find and start eroding the nanotubes, but not so long that it substantially erodes the tube. By switching to the growth conditions, the corrosion back-in process is reversed. At this point, the catalyst particles were catalytically active at the end of the tube (although it was a reverse process), thus occupying an optimal location with respect to the tube end.

  The catalyst can also be supplied in the form of a metal complex that is stable with catalyst precursors, such as oxides, other salts or ligands, that convert to an active form under growth conditions. By way of example, transition metal (primary, secondary or tertiary) alkylamine complexes can be used. Similar alkyl amine complexes of transition metal oxides can also be used.

In an alternative embodiment, the catalyst may be supplied as pre-formed nanoparticles (ie, particles having a diameter of a few nanometers) as described in Dai.
In the next step of the method of the present invention, the single-walled nanotube molecular array with the catalyst deposited on the open tube ends is subjected to tube growth (elongation) conditions. This may be done with the same device on which the catalyst is deposited or with a different device. The apparatus for carrying out the method maintains, at a minimum, the carbon-containing feedstock and the continuous yarn growth end to grow and the carbon from the vapor is directed to the individual nanotube growth end under the direction of the transition metal catalyst. There is a need for a means of maintaining an annealing temperature that can be added to the surface. Typically, the apparatus also has a means for continuously collecting carbon fibers. The method will be described with reference to the apparatus shown in FIGS. 6 and 7 for exemplary purposes only.

  The carbon supply required to grow the single-walled nanotube array into a continuous yarn is in gaseous form from the inlet 11 to the reactor 10. The gas stream should be directed toward the front of the growth array 12. The gaseous carbon-containing raw material can be any hydrocarbon or mixture of hydrocarbons including alkyls, acyls, aryls, aralkyls, etc. as described above. Hydrocarbons having about 1 to 7 carbon atoms are preferred. Particularly preferred are methane, ethane, ethylene, acetylene, acetone, propane, propylene and the like. Most preferred is ethylene. Carbon monoxide can also be used and is preferred for some reactions. The use of pre-prepared molybdenum-based nano-catalysts with carbon monoxide feeds is believed to follow a reaction mechanism that is different from the proposed reaction mechanism for in-situ formed catalyst clusters. Reference die (Dai).

  The feed concentration is preferably selected to maximize the reaction rate, the higher the hydrocarbon concentration, the faster the growth rate. Generally, the partial pressure of the source material (eg, ethylene) can be in the range of 0.001 to 1,000.0 Torr, preferably in the range of about 1.0 to 10 Torr. The growth rate is a power of the temperature at the tip of the growth array, as described below, and as a result, the growth temperature and raw material concentration balance to provide the desired growth rate.

  Preheating the carbon feed gas is not necessary but is preferred because unnecessary pyrolysis at the reactor wall can be minimized. The only heat supplied for the growth reaction should be concentrated on the fiber growth tip 12. The remainder of the fiber and the reactor can be kept at room temperature. Heat can be supplied locally by any preferred means. For small fibers (less than 1 millimeter in diameter), a laser 13 focused at the growth end (eg, a CW laser such as a 514 nanometer argon ion laser) is preferred. For larger fibers, heat can also be supplied by microwave energy or high frequency energy localized at the growth fiber tip. Any other form of concentrated electromagnetic energy (eg solar energy) that can be focused at the growth tip can be used. However, care should be taken to avoid electromagnetic radiation that is sensed and absorbed by the source gas.

  The tip of the single-walled nanotube array should be heated to a temperature sufficient to cause growth and efficiently anneal the growing fiber defects, resulting in the formation of a growth and anneal zone at the tip. In general, the upper temperature limit is governed by the need to avoid thermal decomposition of the raw materials and reactor fouling or evaporation of the deposited metal catalyst. For most raw materials, this temperature is less than about 1,300 ° C. The lower limit of the acceptable temperature range is typically about 500 ° C., depending on the feedstock and catalyst efficiency. A temperature in the range of about 500 ° C to about 1,200 ° C is preferred. More preferred is a temperature in the range of about 700 ° C to about 1,200 ° C. Most preferred is a temperature in the range of about 900 ° C to about 1,100 ° C. This is because the best annealing of defects occurs at these temperatures. The temperature at the growth end of the cable is preferably monitored and controlled in response to an optical pyrometer that measures the resulting incandescence. Although not preferred due to possible contamination problems, under certain circumstances it is possible to use an inert cleaning gas such as argon or helium.

  Generally, the growth chamber pressure is in the range of 1 millimeter to 1 atmosphere. The total pressure should be maintained at 1 to 2 times the partial pressure of the carbon source. A vacuum pump 15 can be provided as shown. It is desirable to recycle the raw material mixture to the growth chamber. Once grown, the fibers can be removed from the growth chamber 16 by suitable transport mechanisms such as drive rolls 17 and idler rolls 18. The growth chamber 16 communicates directly with a vacuum feed lock zone 19.

The growth chamber pressure can be brought to atmospheric pressure in the vacuum horizontal feed if necessary by using a series of chambers 20. Each of these chambers is separated by a loose Teflon O-ring seal 21 surrounding the moving fibers. The pump 22 equalizes the differential pressure. The take-up roll 23 continuously collects carbon fiber cables at room temperature. Product output of the process can range from 10 ^{−3 to} 10 ¹ feet or more per minute. With this method, continuous carbon fibers composed of single-walled nanotube molecules can be produced daily at a rate of tons.

  Fiber growth can be stopped at any stage (to facilitate the production of a specific fiber length or when too many defects have occurred). To resume growth, the edge can be cleaned (reopened) by oxidative erosion (chemical or electrochemical). The catalyst particles are then formed again at the open tube end and continue to grow.

  The molecular arrangement (template) may be removed from the fiber before or after growth by macroscopic physical separation means, for example, by cutting the fiber with scissors to the desired length. Any piece of fiber can be used as a mold to begin production of the same type of fiber.

  The continuous carbon fibers of the present invention can also be grown from one or more separately prepared molecular arrays or templates. The multi-arrays may be the same or different with respect to the type of single-walled nanotubes or the geometry of the arrays. Large cable-like structures with enhanced tensile properties can be grown from a number of smaller isolated arrays as shown in FIG. In addition to the shielding and coating techniques described above, for example, as shown in FIG. 9, the central array of metallic single-walled nanotubes is a series of smaller circular nonmetallic single-walled nanotubes in a ring arrangement around the central array. It is also possible to prepare a composite structure by surrounding with.

All structures contemplated by the present invention need not necessarily have a two-dimensional cross-section that is circular or even symmetric. It is even possible to align the multi-array seed template to cause non-parallel growth of single-walled nanotubes in some parts of the composite fiber, resulting in, for example, a twisted helical rope is there. As described above in connection with the formation of the template array, macroscopic carbon fibers can also be grown in the presence of an electric field to help align single-walled nanotubes in the fibers.
Irregular growth of carbon fibers from single-walled nanotubes The continuous growth of regular bundles of single-walled nanotubes as described above is desirable for many applications, but the random growth of single-walled nanotubes, including individual tubes, ropes and / or cables. It is also possible to produce useful compositions containing oriented materials. The random growth method has the ability to produce large quantities, i.e. tons / day of single-walled nanotube material.

In general, the irregular growth method is to prepare a plurality of single-walled nanotube species molecules supplied with an appropriate transition atom catalyst as described above, and to increase the single-walled nanotube species molecules to several orders of magnitude, for example, the initial length. It includes being subjected to a condition of extending from 10 ^{2 to} 10 ¹⁰ times or more.

  The seed single-walled nanotubes are preferably produced as described above, for example, by cutting continuous fibers or purified “bucky paper”, preferably in a relatively short length. In a preferred embodiment, seed molecules can be obtained after the first run from single-walled nanotube felt produced by the present random growth method (eg, by cutting). The length need not be uniform and is generally in the range of about 5 nanometers to 10 microns long.

  These single-walled nanotube molecules are formed on a macroscale or nanoscale support that does not participate in the growth reaction. In another embodiment, multiple or single single-walled nanotube structures can be used as a support material and species. For example, the self-assembly techniques described below can be used to form three-dimensional single-walled nanotube nanostructures. Nanoscale powders produced by these techniques have the advantage that the support material can participate in irregular growth processes.

  A supported or unsupported single-walled nanotube seed material can be combined with a suitable growth catalyst as described above by opening the ends of single-walled nanotube molecules and depositing metal atom clusters. Alternatively, the growth catalyst can be fed to one or both ends of the open seed molecule by evaporating a suspension of the seed in a suitable liquid containing a soluble or suspended catalyst precursor. it can. For example, when the liquid is water, soluble metal salts such as ferric nitrate, nickel nitrate, and cobalt nitrate are used as the catalyst precursor. In order to ensure that the catalytic material is correctly positioned on the open end of the single-walled nanotube seed molecule, the single-walled nanotube end is coated with catalyst nanoparticles, or more preferably with ligand stabilized catalyst nanoparticles. It may be necessary under some circumstances to derivatize with a moiety that binds.

  In the first step of the random growth method, a suspension of seed particles containing attached catalyst or associated with dissolved catalyst precursor is injected into the evaporation zone where the mixture contacts the cleaning gas stream And heated to a temperature in the range of 250 ° C. to 500 ° C. to flash evaporate the liquid to provide entrained reactive nanoparticles (ie, seed / catalyst). Optionally, this entrained particle stream is subjected to a reduction step and the catalyst is further activated (eg, heated at 300 ° C. to 500 ° C. in hydrogen). Next, the carbonaceous source gas of the type used in the continuous growth method is introduced into the cleaning gas / active nanoparticle flow, and the mixture is transported to the growth zone by the cleaning gas and further passed through the growth zone.

  The reaction conditions in the growth zone are as described above, ie, 500 ° C. to 1,000 ° C. and a total pressure of about 1 atmosphere. The partial pressure of the source gas (eg, ethylene or carbon monoxide) is in the range of about 1 to 100 torr. The reaction is preferably carried out in a tubular reactor, through which a cleaning gas (eg argon) flows.

  The growth zone consists of (1) preheating the source gas, (2) preheating the cleaning gas, (3) heating the growth zone from the outside, and (4) for example by laser or induction coil or a combination thereof. By applying localized heating in the growth region, it is possible to maintain an appropriate growth temperature.

The downstream recovery of the product produced by this method can be performed by known means such as filtration and separation by a centrifuge. Purification can also be achieved as described above. Felt made by this disordered method is used to produce composites such as polymers, epoxies, metals, carbon (ie carbon / carbon materials) and high T _ζ superconductors for flux pinning be able to.
Macroscopic carbon fibers The macroscopic carbon fibers produced as described herein preferably consist of agglomerates of a number of single-walled nanotubes, preferably generally in parallel orientation. Individual nanotubes may deviate from parallel orientation relative to other individual nanotubes, especially at very close distances, but over macroscopic distances, the average orientation of all nanotubes is generally Parallel to all other nanotube orientations in the aggregate (the macroscopic distance described here is generally considered to be greater than 1 micron). In a preferred form, the single-walled nanotubes are arranged in a regular triangular lattice, that is, in a close-packed relationship.

  The carbon fiber of the present invention is composed of individual cylindrical molecules, and the whole or part of the structure is crystalline or amorphous. The degree of order of the fibers depends on both the tube geometry in the molecular arrangement and the growth and annealing conditions. The fibers can be subjected to orientation or other secondary treatment before or after collection. The fibers produced by this method can be further spun or braided into larger yarns or cables, for example. The as-manufactured fibers are also considered to be of a sufficiently large diameter for many applications.

In general, the macroscopic carbon fibers produced according to the present invention consist of a sufficient number of substantially parallel single-walled nanotubes to be practically treated as individual fibers and / or to larger continuous products. The diameter is large enough to process. The macroscopic nature of the nanotube population is also important for end uses such as current transmission in these nanotubes. The macroscopic carbon fiber according to the present invention preferably comprises at least 10 ⁶ single-walled carbon nanotubes, more preferably at least 10 ⁹ single-walled carbon nanotubes. The number of assembled nanotubes is much greater than the number that naturally aligns (less than 10 ³ ) while forming single-walled nanotubes in carbon vapor condensing in a carbon arc or laser evaporator. For many applications, the preferred diameter of the macroscopic carbon fiber of the present invention is in the range of about 1 to about 10 microns. For some applications, such as power transmission cables, fiber diameters up to several centimeters are required. It is also possible to contain dopants such as metals, halogens, ferric chloride, etc. that are physically confined between fiber tubes.

  The macroscopic carbon fibers of the present invention are typically at least 1 millimeter in length, and the exact length depends on the particular application for which the fiber is used. For example, when the conventional fiber is designed to replace the conventional graphite carbon fiber for reinforcement, the fiber length according to the present invention is similar to the conventional carbon fiber length. When the macroscopic carbon fiber according to the invention is used for electrical conductivity, the fiber length preferably corresponds to the distance for which electrical conductivity is required. Typically, such distance is 1 to 100 microns or more, or 1 to 10 millimeters or more. When electrical conductivity over a macroscopic distance is required, the macroscopic carbon fiber according to the present invention preferably has a length of order of meters or more.

One reason that the continuous carbon fibers of the present invention have such improved physical properties is their structure of high order laminates, i.e. many individual cylindrical molecules greater than 10 ⁹ are laminated together. . This structure provides much higher flexural strength, higher chemical corrosion resistance, better wear resistance, higher elasticity, and a tensile failure mechanism that is completely different from similar monolithic materials. The single-walled carbon nanotube fibers of the present invention provide low weight and extremely high tensile strength (weight is only 1/6 but up to 100 times stronger than steel). This fiber has a conductivity similar to copper. Furthermore, the thermal conductivity of the fiber is approximately that of diamond. Carbon fiber of the present invention also has a (better than such spherical fullerenes C ⁶⁰ to C ⁷⁰⁾ high chemical resistance. In general, continuous carbon fibers that do not have the defects of the present invention exhibit improved physical properties over conventional carbon fibers because of the nearly complete multi-hexagonal structure that extends over macroscopic distances.

  In a special embodiment, the macroscopic carbon fiber according to the invention has a region substantially containing armchair-oriented single-walled nanotubes, and the region has a diameter of at least 1 micron, preferably at least 100 microns. It is grown from a molecular array containing a self-assembled monolayer. By using a shielding film on the surface where the single layers are assembled, the region including the armchair single-walled nanotube is completely surrounded by the coaxial region of the tube having a chiral type or zigzag type structure. This extension from the mold yields a conductive core surrounded by a semiconducting or insulating sheath, with each layer consisting essentially of a single molecule of indefinite length. A coaxial transmission cable having several layers can be manufactured in a similar manner.

  Applications of these carbon fibers include applications where graphite fibers and high strength fibers are currently used, such as membranes for batteries and fuel cells; chemical filters; catalyst supports; hydrogen storage ( Used as absorbent material and also in the production of high pressure containers); lithium ion batteries; and capacitor membranes. These fibers can also be used in electrochemical devices such as nanostrain gauges (which are sensitive to either bending or twisting of the nanotubes). The fiber of the present invention can be used as a product as it is or after being spun into threads using a known fiber technique or formed into yarns.

The carbon fiber technology of the present invention also facilitates the production of a new class of composites using hexaboron nitride lattices. This material forms a graphene-like sheet having a hexagon consisting of boron and nitrogen atoms (eg B ₃ N ₂ or C ₂ BN ₃ ). Providing an outer coating on the growth carbon fiber by supplying a boron nitride precursor (eg, trichloroborazine, a mixture of ammonia and boron trichloride or diborane) to the fiber that serves as a deposition mandrel for the boron nitride sheet. Is also possible. This outer boron nitride layer provides enhanced insulating properties for the metallic carbon fibers of the present invention. It may be used to provide an outer layer of a pyrolytic carbon polymer or polymer blend. By converting the feedstock from hydrocarbon to boron nitride and then back to hydrocarbon in the above method of the present invention, fibers of individual nanotubes with alternating regions of all carbon and boron nitride lattices are obtained. It is possible to grow. In another embodiment of the invention, the growth of all boron nitride fibers can be initiated with a single-walled nanotube template array apexed with a suitable catalyst and supplied boron nitride. These graphene and boron nitride systems can be mixed to fit very closely in size with the structure of the two hexagonal units. In addition, the thermal expansion coefficient and tensile properties closely match so that they exhibit enhanced physical properties. Boron nitride fiber can be used as a reinforcement enhancer in many other applications described above for composites and carbon fibers.
Device technology enabled by the product of the present invention The unique physical properties of the present invention's cylindrical carbon molecules, molecular arrangements and macroscopic carbon fibers provide exciting device fabrication opportunities.
1. Power Transmission Cable Power transmission line designs typically use aluminum conductors, which often have steel strand cores for reinforcement (ie, so-called “ASCR conductors”). This conductor has a greater loss than the copper conductor and is generally not shielded, leading to corona discharge problems. Continuous carbon fibers formed from large (greater than 10 ⁶ ) aggregates of single-walled nanotubes can be used to fabricate power transmission cables with unique designs and characteristics. One such design is shown in FIG. This design enables extra high voltage (EHV) (ie, greater than 500 kilowatts, preferably greater than 10 ⁶ volts) power transmission, and strength-to-weight not previously obtained (strength- It is essentially a shielded coaxial cable with to-weight characteristics and little or no corona discharge problems.

  The illustrated design illustrates the use of a carbon fiber conductor based on a single-walled nanotube fabricated as described above [eg, from (n, n) -type metallic single-walled nanotubes] It consists of a coaxial outer conductor 31 separated by an insulating layer 32. The center conductor conducts power transmission, and the outer layer conductor is biased to the ground. The central conductor can be solid metallic carbon. Alternatively, the central conductor can contain metallic carbon fiber strands that may agglomerate in the usual spiral of ACSR conductors.

  The inner conductor may also contain an annular tube woven or braided with metallic carbon fibers as described above and surrounding the exposed heart space. The insulating layer can be any lightweight insulating material. In a preferred embodiment, a boron nitride strand bundle or woven fabric layer is fabricated as described above and an annular air space (formed using an insulating spacer) is used.

  The outer conductor layer is also preferably made of a helically wound strand of metallic carbon fiber as described above. This grounded layer essentially eliminates the corona discharge problem or the need to take conventional measures to reduce its emissions.

  The resulting coaxial structure possesses extremely high weight strength characteristics and can be used to transmit higher power levels over longer distances with less loss compared to conventional power levels. .

One of the power cable assemblies can be used to replace each conductor used for separate phases in a conventional power transmission system. It is also possible to provide a single power transmission cable that conveys more than three phases by manufacturing a multilayer annular cable having alternating metallic carbon fiber conductors and insulating layers, and greatly simplify the installation and maintenance of power lines .
2. Solar cell The type of Gratzel cell described in US Pat. No. 5,084,365 (which is hereby incorporated by reference in its entirety) is a single-walled molecular array of short carbon nanotube molecules as described above. It can be made using nanocrystalline titanium dioxide that has been replaced. The light energy impinging on the tube is converted into an oscillating electron stream that travels along the length of the tube, so there is no need to use a photoactive dye. The ability to provide large charge separation (array tube length) creates a highly efficient battery. To further increase the efficiency of the battery, a photoactive dye (eg, cis- [bisthiocyanate bis (4,4′-dicarboxy-2,2′-bipyridine) attached to the end of each nanotube in the array. The use of Ru (II))] is also contemplated by the present invention.In another embodiment of the present invention, the titanium dioxide nanostructure described by Glacier has an array of single-walled nanotubes. In this embodiment, the single-walled nanotubes are attached directly to the titanium dioxide (by absorption) or are first derivatized to give a binding moiety, and then It binds to the surface of the titanium dioxide and can be used with or without a photoactive dye as described above.
3. The structure encapsulating the charge inside the tubular carbon molecule described above can be used to form the bit structure of a nanoscale bistable nonvolatile memory device. One embodiment of this type of bit structure is to enclose an appropriate molecule in a tubular carbon molecule, closing the end of the tubular carbon molecule, and providing control influence from outside the tubular carbon molecule. By acting, one encapsulated molecule can be moved back and forth inside the tubular carbon molecule. In another embodiment, a plurality of magnetic nanoparticles (for example, Ni / Co) are encapsulated in a tubular carbon molecule having a relatively short length. The nanobit used can be formed.

  FIG. 11 shows one preferred embodiment of this type of bit structure. In this bit structure, the physical dimensions of the tubular carbon molecule 40 are such that the internal moving body 41 enclosed therein can move smoothly, that is, it is too thin to prevent the internal moving body 41 from moving. It is sized so that it never happens. The selection criteria for the internal moving body are (1) that it is convenient for the read / write system used to read / write the bit, and (2) that it is compatible with the electronic structure of the tubular carbon molecule. There is one.

One suitable example of such a nanobit structure is C ₆₀ in a short (eg, about 10-50 nm long) tubular carbon molecule formed from (10,10) SWNTs according to the process described above. or put C ₇₀ spherical fullerene molecule is obtained by encapsulating the spherical fullerene molecule to close the end of the tubular carbon molecules. In this case, an appropriate doping may be applied to the inner or outer surface of the C ₆₀ or C ₇₀ molecule (bucky ball) to be encapsulated. (10,10) When a C ₆₀ buckyball is placed inside a nanotube, both sizes fit almost perfectly. Another important thing about this combination is that the electronic environment inside the nanotube is highly compatible with the electronic environment of the bucky ball. In particular, the electronic environment inside the closed end of the nanotube fits well with the electronic environment of the bucky ball, because the curvature of the inner surface of the end cap portion of the (10,10) nanotube is C ₆₀ This is because it corresponds to the curvature of the outer surface of the buckyball. According to this configuration, the interaction between the two due to the van der Waals force is optimal. As shown in FIG. 12, the amount of energy required to remove the bucky ball that is stuck in the end cap portion of the nanotube from there to the intermediate cylindrical portion (the bucky ball fits into the end cap). This bit structure becomes a bistable bit structure when the threshold value is the electronically stable state.

FIG. 11 shows an example of a suitable read / write structure suitable for performing read / write operations on the memory bits described above. To write to a memory bit, a voltage pulse of the appropriate polarity is applied to the memory bit via a nanocircuit element 42 (which is preferably formed of SWNT molecules). When a positive voltage pulse is applied, an attractive force acts on the bucky ball, and when a negative voltage pulse is applied, a repulsive force acts on the bucky ball. Because the memory bit is bistable, the bucky ball remains at the end of the nanotube that was located at the end, even after extinguishing the voltage pulse. This is because both ends of the nanotube are at the lowest energy positions. In order to read from the memory bit, a bias voltage V _READ is applied to another nanocircuit element 43 (which is also preferably formed of SWNT molecules). If the bucky ball was then located at the detection end of the nanotube ends, the current was joined by resonant tunneling due to the energy level imparted by the application of this bias voltage. And flows to the ground potential 44 (this current flow is generated in the same manner as the current flow in the resonant tunneling diode). This reads that the memory bit is in the first stable state. On the other hand, if the bucky ball is not positioned at the detection end, the energy level applied by the application of the bias voltage is deviated from the resonance point. It does not flow through, thereby reading that the memory bit is in the second stable state. As will be readily understood by those skilled in the art, other forms of read / write structures (for example, microactuators) other than those described above may be used.

A memory device can be constructed by arranging the bit elements shown in FIG. 12 to form a two-dimensional array or a three-dimensional array. Such a memory array can have a very high bit density because each bit element is very small (eg, can be about 5 nm × 25 nm), eg, 1.0 terabit / cm ² or more (this is the case when the bit interval is 7.5 nm, for example). The distance that the buckyball must move to operate the memory device is only a few nanometers, and the mass of the buckyball is so small that the write time of the above memory device is about ^10-10 seconds become.
4). Lithium-ion battery The present invention further relates to a lithium-ion secondary battery, wherein the lithium-ion secondary electrons arrange a large number of SWNT molecules in the manner described above (eg, using SAM techniques). The SWNT array is used as a negative electrode (anode) material. The anode material, for example, a large number of (for example, 10 ³ or more) relatively short nanotube molecules, may be formed by the Hani設on the substrate. Alternatively, the end of the fine carbon fiber described above can be used as the fine porous surface of the negative electrode.

This nanotube molecular array can be a molecular array composed of open tubular carbon molecules with open ends, or a molecular array composed of closed tubular carbon molecules with closed ends. it can. In either case, the individual tubular carbon molecules provide structurally stable pores for intercalating lithium ions (incorporating in the form of intercalation compounds). That is, in a molecular array using an open tubular carbon molecule, lithium ions enter and intercalate into the tubular carbon molecule, and in a molecular array using a closed tubular carbon molecule, lithium ions • Ions enter and intercalate into the triangular pores formed in the end caps of the tubular carbon molecules. Combining the fullerene intercalation compound (FIC) formed by this intercalation with, for example, an aprotic organic solvent electrolyte containing lithium ions and a positive electrode (cathode) made of LiCoO ₂ Thus, an excellent lithium ion secondary battery can be constituted. In addition, this lithium ion secondary battery is a secondary battery of the type explained in the lecture of Mr. Nishi made in 1996 at the IEEE, VLSI circuit symposium entitled "The Development of Lithium Ion Secondary Batteries" This is shown in FIG. In the figure, the negative electrode 50 is composed of a molecular array in which a large number of SWNTs 51 are aligned. Other components of the secondary battery are a positive electrode 52, an electrolytic solution 53, lithium ions 54, and electrons 55.

  The lithium-containing medium comprising the molecular array FIC according to the present invention has a large charge capacity (for example, 600 mA h / g or more), excellent stability during charging, and excellent cycle characteristics. Therefore, an excellent storage battery having high safety can be configured by using this lithium-containing medium.

  The negative electrode described above is an electrode formed from carbon molecules having a large maximum current, a large charge capacity, a low resistance, and an excellent reversibility, and having a complete molecular structure by nanoengineering. is there. This negative electrode has a membrane (film body) formed by aligning fullerene and nanotube molecules having metallic material properties so as to form a nail bed type array. In the interior of each nanotube, lithium ions are accommodated inside the pores. In addition, when using nanotubes with an open end, the chemical modification treatment applied to the open end is optimized to improve the characteristics of the interface between the negative electrode and the electrolyte. Can be. The modified substance added by this modification treatment is preferably an organic substance that can provide an interface where a redox reaction occurs as a stable interface. In general, it is preferable that the organic substance used as the modified substance has a structure similar to that of the electrolysis solution used. A preferred example of the agent used for the modification treatment is polyethylene oxide, and it is particularly preferable to use an oligomer of polyethylene oxide.

  For the use as an electrode, an electrochemical reaction of a nanotube membrane formed by using nano engineering is used. The important point in this regard is that the end surfaces and side surfaces of the nanotube molecules are modified so that an optimal interface suitable for the electrolyte used in the lithium ion secondary battery is formed. That is. This facilitates the attachment of lithium ions to the battery electrode, thereby increasing the energy density. Furthermore, it is equally important that it overcomes the so-called SEI (solid-electrolyte intermediate phase) problem that has always been plagued. When this SEI problem occurs, the capacity of the electrode is significantly reduced, and the reversibility of the electrode is significantly deteriorated.

Li ⁺ has excellent characteristics as ions used in storage batteries. That ions having properties superior to Li ⁺ as counter-ions of the lighter is not in addition to protons, and the Li ⁺ is the electrolyte used can be selected very out of the electrolyte of many kinds of solid and liquid The advantage is that the positive electrode material can also be selected from a very large variety of materials. The main materials that can be used as the positive electrode material are various metal oxides in which the intercalation sites form a three-dimensional network structure. The place where Li + enters when it is in a discharged state. Early rechargeable lithium batteries used metallic lithium as the anode material, but such batteries were associated with the disadvantages listed below.

-Dendrites grow during recharging, so that the lithium making up the electrodes is gradually lost.
-Because of the use of organic solvents, severe lithium reactivity is a safety issue.

-As mentioned above, since lithium dendrite grows, the separator may be broken and the positive electrode and the negative electrode may be short-circuited.
Among these problems, a method found as one of the solutions to the safety problem is to replace the negative electrode material from lithium metal to lithium-carbon intercalation compound. The battery was developed. In a rocking chair battery, Li ⁺ is not reduced to Li ^0, and when the battery repeats charging and discharging, a negative electrode intercalation site formed using a carbon material, and a metal material Li ⁺ simply reciprocates between the positive electrode formed by using. In the first generation lithium-ion secondary battery, graphite was used as the carbon material, but the main reason for the choice of graphite was already the solid-state chemical reaction between lithium and graphite. It was because it was elucidated. Fortunately, the potential of Li ⁺ in graphite is within tens of times the MV of the potential of Li ⁰ , so even if black smoke is used instead of metallic lithium, the increase in weight and volume is caused thereby. The reason is that the battery voltage is not significantly reduced.

However, the fact that black smoke is used has caused the following new technical problems.
- electrolyte having excellent transport properties for moving the Li ⁺ at room temperature (e.g., a solution obtained by dissolving LiClO ₄ in propylene carbonate) from causing the solvated against Li ^+, graphite intercalation compounds with Li ⁺ Form. Therefore, exfoliation of graphite is generated, dimensional stability is impaired, and early failure is induced.

-Li ⁺ diffusion in graphite at room temperature is relatively low. This is because the barrier when jumping from a position surrounded by one hexagonal structure in a graphite lattice to a position surrounded by a hexagonal structure adjacent to it is compared (compared to a lattice with a similar structure). This is because diffusion is suppressed due to the large size.

The first of these two problems is a new electrolytic solution that does not form a graphite intercalation compound with Li ⁺ (for example, an electrolytic solution in which LiPF ₆ is dissolved in a mixed solution of dimethyl carbonate and ethylene carbonate). However, such electrolytes have inferior transport ability to move ions. Moreover, in order to overcome the second problem, it is necessary to use graphite in a finely divided form (that is, powder, crushed pieces, fibrous form, porous form, etc.). Increases significantly, thereby creating a new set of problems. Among these problems, for example, when a graphite intercalation compound is formed on the negative electrode in the first charging half cycle, a thin surface layer (so-called “solid-electrolyte intermediate phase: SEI”) is formed. There is a problem that the capacity is reduced. In order to overcome this problem, the amount of the lithium-containing material used for the positive electrode must be increased by the amount of lithium consumed by the formation of SEI rather than the theoretical amount when manufacturing the battery. Even so, the capacity decreases. Not much is known about this SEI, but it is generally accepted that carbonate (produced by the decomposition of the electrolyte) is an important component of SEI. Also, a widely adopted industry standard for SEI is to ensure that the capacity loss due to SEI formation does not exceed 10% of the capacity when all lithium is used.

  Further research has found that various other forms of carbon (nanocrystalline carbon) can be used. Among them, carbon black, calcined coal, calcined petroleum pitch, calcined polymer, calcined natural raw materials (sugar, nut peel, etc.), carbon and other elements (boron, silicon) , Oxygen, hydrogen) and the like. Furthermore, it has been found that completely new systems such as tin oxide can be used. Some of these materials have a lithium capacity that is greater than that of graphite, but little has been clarified about the microscopic causes of their “increased capacity”. In general, these materials are much inferior in cycle characteristics to graphite, and any of these materials that contain hydrogen has a relationship between battery voltage and lithium concentration that has a charge half cycle. And the discharge half cycle are greatly different, that is, exhibit a remarkable hysteresis characteristic. This is a very inconvenient characteristic as a battery characteristic. Also, almost nothing has been elucidated about the cause of this hysteresis characteristic. The main advantage of these materials is that they are essentially in the form of fine grains or strips, so that lithium ions move quickly inside these materials. This is an absolutely necessary condition when lithium ion secondary batteries are used in high current applications (eg, electric vehicles) and battery performance is an important factor in that application. is there.

The negative electrode according to the present invention is manufactured with nano-level engineering from the beginning to the end with molecular level accuracy. This negative electrode accommodates lithium with an electrochemical potential comparable to that of metallic lithium, has a large lithium capacity per volume, and does not cause the problem of dendritic growth. There is no safety problem associated with the negative electrode formed only of metallic lithium. In this negative electrode, lithium ions move at high speed during charging and discharging, and structural and chemical integrity is maintained regardless of the level of charge or discharge. In addition, since the interface between the negative electrode and the electrolyte can be designed to be in the desired state, the redox chemical reaction represented by Li ⁰ ⇔ Li ⁺ is highly reversible. And can be performed with a very small effective resistance.

To give a specific design example of such a negative electrode, for example, a large number of fullerene nanotubes are aligned on a metal support electrode such as a gold-plated copper plate so as to form an array of hexagonal lattices such as a nail bed. It was made to adhere. As is clear from FIG. 14, according to this structure, Li ⁰ which is reduced lithium is deep in the space defined between the nanotubes or in the hollow space inside the nanotube itself. This is an advantage of this structure. In other words, the region where the chemical reaction of the oxidation and reduction of lithium is performed is limited mainly to the tip portion of the nanotube exposed on the surface of the electrode, and the modification processing is applied to the tip portion of the nanotube. The oxidation-reduction reaction can be highly reversible.
5. Three-dimensional self-aligned SWNT structure In the self -aligned structure (SAM) according to the present invention, a SWNT molecule as a constituent element of the structure is modified, and a number of such SWNT molecules are combined together. There is a three-dimensional self-aligned structure in which the structure is configured spontaneously. One possible embodiment is to use the previously described SAM, i.e. a two-dimensional monolayer structure, as a starting material, i.e. a template, to form the three-dimensional self-aligned structure. When a single-functional modification is added to the end caps of SWNT molecules that are components of this self-aligned structure, the molecules extend in the same direction and align as if the ends of the molecules are abutted. Tend to constitute a three-dimensional structure. On the other hand, when a multifunctional modification is added to the SWNT molecule, or when a modification is added to each of the SWNT molecules at multiple positions on the SWNT molecule, a symmetrical structure is constructed. In some cases, a true three-dimensional structure without symmetry is formed.

  When the carbon nanotubes in the sample manufactured by the method described above are modified, a plurality of functionally-specific agents (FSA) may be bound to each nanotube. The form of the bond can be either an ionic bond or a covalent bond. In addition, with regard to the bonding positions of these multiple FSAs, there are cases where they are bonded together at an arbitrary position on each nanotube and cases where they are individually bonded at an arbitrary series of positions on each nanotube. obtain. By adding FSA, a geometric structure can be formed by self-alignment of the nanotube group. A single structure can be formed by combining nanotubes having a plurality of lengths, and a single structure can be formed by combining nanotubes to which different types of FSA are added. In addition to self-alignment by the action of FSA, it is also possible to self-align by van der Waals force, and van der Waals force is modified between the modified fullerene molecules. Self-alignment can be performed between fullerene molecules that have not been treated, and between fullerene molecules that have undergone modification treatment and fullerene molecules that have not undergone modification treatment. Also, by utilizing the selective binding of FSA, only specific size or specific type of nanotubes (target nanotubes) can be aligned, and non-target nanotubes can be excluded from the alignment structure even if they exist. Is possible. Thus, one embodiment is to select a FSA that aligns nanotubes of a specific length. Further, by combining a plurality of FSAs having such selectivity, it is possible to align two or more different sizes or types of carbon nanotubes so as to extend in a certain direction.

  FSA can affect both carbon nanotubes that have not been modified and carbon nanotubes that have been modified. Using this FSA action, one can align and A specific three-dimensional structure can be constructed from a group of carbon nanotubes by controlling the extending direction and size of the carbon nanotubes to be structured. Thus, by controlling the three-dimensional geometric structure of the self-aligned nanotube structure using the action of FSA, the mechanical properties, electrical properties, chemical properties, and optical properties have been improved. The possibility of synthesizing a unique three-dimensional nanotube material that does not exist is obtained. The properties of such 3D nanotube materials vary depending on what FSA is used and, if multiple FSAs are used, what interactions occur between the FSAs. Can be a thing.

  Furthermore, after the self-aligned fullerene structure is completed, a part of the structure is chemically or physically modified, or the structure is subjected to physical processing, chemical processing, electrical processing, optical processing. And / or biological treatment can change the properties of the self-aligned fullerene structure. As a method for that, for example, a method in which another molecule is bonded to the self-aligned fullerene structure by ionic bond or covalent bond, a method in which FSA that is no longer needed after the structure is completed, or a method in which the structure is completed, There is a method of modifying a part of the arrangement of the structure by biological treatment or optical treatment. Such structural modification and / or modification process changes the electrical function, physical function, electromagnetic function, or chemical function of the self-aligned fullerene structure, or changes them to the self-aligned fullerene structure. Functionality can be imparted, and further, the interaction between the self-aligned fullerene structure and other devices can be altered or newly imparted.

  This geometric self-aligned structure can provide various excellent electrical characteristics. For example, the operating characteristics as an electric circuit, specific conductive tensor characteristics, electromagnetic radiation, etc. Specific response characteristics, diode junction characteristics, characteristics as a three-terminal device for current control, characteristics as a capacitor constituting a memory element, characteristics as a normal capacitor, characteristics as an inductor, characteristics as a conduction element, It has characteristics as a switch.

  This geometric self-alignment structure can further provide various electromagnetic characteristics, such as a characteristic as a conversion element that converts electromagnetic energy into a current, and an antenna as an antenna. Characteristics, characteristics as an antenna array, characteristics as an array that decomposes into electromagnetic waves of various wavelengths by generating coherent interference of electromagnetic waves, characteristics as an array that selectively changes the propagation state of electromagnetic waves, or optical fiber There is a characteristic as an element that causes an interaction with the. These electromagnetic characteristics differ depending on the FSA used, and when a plurality of FSAs are used, various characteristics are obtained depending on the interaction between the FSAs. For example, by appropriately determining the length, position, and orientation of the individual molecules that make up the molecular array using FSA, they are induced inside the molecules by electromagnetic fields in the vicinity of the molecules, respectively. The phase relationship between the induced currents can be a predetermined phase relationship. Further, in this case, the electric induction flows induced inside the molecules exhibit behaviors according to the spatial distribution of the phase angle and frequency of the electromagnetic field. In addition, the phase relationship between the induced currents induced inside each molecule is also affected by the structure of the molecule array. In addition, it is possible to use FSA to reinforce various interactions between individual nanotubes or groups of nanotubes and those that are present externally. It is an action that transmits stress, strain, electrical signal, current, or electromagnetic interaction in some form. Such interactions provide an “interface” between this self-aligned nanostructure and other known useful devices.

  Furthermore, by appropriately selecting FSA, a geometric structure having excellent chemical or electrochemical characteristics can be formed by self-alignment, and such chemical characteristics or electrochemical characteristics can be achieved. For example, there are characteristics when acting as a catalyst in a chemical reaction or electrochemical reaction, absorption characteristics of a specific chemical substance, resistance to attack from a specific chemical, energy accommodation characteristics, and corrosion resistance.

  Specific examples of useful biological properties of structures constructed by self-alignment using FSA include properties when acting as a catalyst for biochemical reactions, absorption sites for specific biochemicals, agents or structures Characteristics related to reaction sites, characteristics related to effects as drugs or therapeutic agents, characteristics related to the occurrence of specific interaction or non-specific interaction with living tissue, growth of biological systems in some form There are characteristics as an agent for causing the function to occur, and characteristics as an agent that causes an interaction with the electrical function, chemical function, physical function, or optical function of a known biological system.

  Furthermore, a structure configured by self-alignment using FSA can have useful physical properties. As a specific example thereof, there is a case where the elastic stress tensor, which is the ratio of elasticity to specific gravity, can be set to a large value, and is not limited thereto. In addition, the self-aligned structure can have useful optical properties, such as light absorption spectral properties, light transmission spectral properties, and changing polarization state. There is a characteristic to make it.

By utilizing this self-aligned structure or the above-mentioned fullerene molecule alone or in combination, the various forms of self-aligned structure, fullerene molecule, or a combination of both are collectively referred to as “molecule / structure”. A variety of devices with useful properties can be fabricated. For example, one molecule / structure and one molecule / structure can be attached to another molecule / structure by binding it to another structure via physical, chemical, electrostatic, or magnetic means. Physical means, chemical means, electrical means, optics between or between other bonded structures, or between one molecule / structure and something in the vicinity of that molecule / structure It is possible to enable information transmission via an artificial or biological means. Specific examples of such information transmission include physical information transmission by magnetic interaction, chemical information transmission by reaction of an electrolyte or chemical agent in a solution, electrical information transmission by movement of an electron charge, For example, there is optical communication by interaction with a biological agent or delivery of a biological agent, and information transmission through the agent is performed between the molecule / structure and the one to which the agent reacts. become.
6). SWNT antenna fullerenes / nanotubes can be used instead of conventional conductor antenna elements. For example, (n, n) nanotubes can be used in combination with other materials to form a Schottky barrier that functions as a light harvesting antenna. One embodiment is to form a natural Schottky barrier by bonding gold at one end of the (10,10) nanotube and lithium at the other end, both via a sulfur bridge. is there. Thereby, current can be generated by photoconductivity. (10,10) Nanotubes function in the same way as antennas and function to inject electrons into the electrodes by a pumping action. Therefore, backflow of electrons is prevented.

  To form an antenna, the length of the nanotube molecule is adjusted so that its final electrical length is the desired length. In this case, the electrical length of the nanotube molecule is selected by the fact that the current flowing inside the nanotube molecule interacts with the electromagnetic field in the vicinity of the nanotube molecule, so that the energy of the electromagnetic field becomes the internal current of the nanotube molecule. And conversely, the internal current of the nanotube molecule is converted to the energy of the electromagnetic field. Furthermore, when selecting the electrical length of the nanotube molecule, the current of various frequencies induced in the antenna circuit is selected so that the current of the frequency included in the desired frequency region is maximized, Or, the voltage of various frequencies generated in the antenna circuit is selected so that the voltage of the frequency included in the desired frequency region is maximized, and the current and voltage are appropriately increased so as to increase moderately. Sometimes it is designed to make a compromise.

  The fullerene-nanotube molecular antenna can also be used as a load on certain circuits. In that case, the current flowing into the antenna may be converted into a desired electric field and magnetic field. By adjusting the length of the nanotube, it can have the desired propagation characteristics. Furthermore, the diameter of the antenna element can be adjusted by using a number of nanotubes in bundles.

Furthermore, an antenna array can be configured by combining a large number of antenna elements formed of nanotube molecules as described above. For this purpose, by appropriately selecting the length, position, and orientation direction of the nanotube molecules, the current flowing inside each of the plurality of nanotube molecules can act coherently with a predetermined phase relationship, thereby The electromagnetic field may be generated in the vicinity region of the nanotube molecules, or the electromagnetic field in the vicinity region may be changed. In this case, due to the coherent action of the current flowing inside each of the plurality of nanotube molecules, the spatial distribution, angular distribution, and frequency distribution of the electromagnetic field generated by these currents are determined, changed, controlled, or selected. Is done. In another embodiment, the current induced in the plurality of nanotube molecules has a predetermined phase relationship determined by the shape of the antenna array, thereby generating secondary currents generated by the currents. The electromagnetic field can also be configured to radiate from its antenna array with an appropriate spatial, angular and frequency distribution, in which case the spatial distribution, angular distribution, and The frequency distribution is determined by the form of the antenna array and antenna element. As a method for forming such an antenna array, for example, the self-aligned single layer forming method described above may be used.
7). Fullerene molecular electronics Fullerene molecules also have applications that are used in place of conventional conductive elements. For example, fullerene molecules or self-aligned fullerene molecule groups can be used to form an electric circuit, and charge transfer in the electronic circuit can be performed by the fullerene molecules. In this case, fullerene molecules carry charge between functional elements that change or control the flow of charge in the electric circuit, and carry charge between objects in the electric circuit. Make it. The object here means that the current flow inside it performs some useful function. For example, the useful function is a function that changes the electric field distribution around the object, or an electrical contact of the switch. And the function realized by the object reacting to electromagnetic waves.

  As a specific configuration example, for example, a bridge circuit for full-wave rectification can be formed by self-aligning nanotube molecules. Such a device can be composed of four nanotube molecules, each forming one side of a square, and four bucky balls each placed at one corner of the square. First, the bucky ball and the nanotube molecule are modified to add a specific function agent to each. By the action of the added specific function agent, a bridge that connects the bucky ball to the nanotube molecule is formed, and the bridge is configured in a required form.

Further, a fullerene diode can be formed by using the above-described self-alignment method. The diode can be composed of, for example, two bucky tubes and one bucky capsule. In that case, the bucky capsule is first modified to make it a bipolar ion. Specifically, a bipolar ion can be formed by adding two positive groups such as triethylamine cation and two negative groups such as CO ₂ -anion to a bucky capsule. Further, in one embodiment, one (10,10) bucky tube is attached to each end of the bucky capsule via a disulfide bridge. In this configuration, sulfur serves as a specific function agent.
8). Probes and Manipulators Further, nanoscale probes and manipulators can be produced using the SWNT molecules according to the present invention. Specific examples thereof include a probe tip of an AFM apparatus and an STM apparatus, a cantilever of an AFM apparatus, and the like. Further, if the above-described modification treatment is applied to such a probe, it can function as a sensor or sensor array having a property of selectively adhering to a substrate. Such a device can be used for high-speed screening efficacy tests and the like in which efficacy tests for biologically active substances such as pharmaceuticals are performed at the molecular level. Furthermore, the conductive SWNT molecule according to the present invention can also be used as an electrochemical probe.

Similarly, a probe-like assembly composed of SWNT molecules, whether modified or not, can be used as an effective tool for material handling and manufacturing of nanodevices such as nanoforceps. it can. Furthermore, this type of molecular tool can also be used to manufacture MEMS (micro electro mechanical systems) and to connect NANO-MEMS components or circuit components.
9. A composite material containing carbon nanotubes A composite material is a material composed of two or more kinds of different component materials, and various materials are known. In general, a composite material is composed of a base material that defines the overall shape of the composite material and a load bearing material that determines the internal structure of the composite material. If stress acts on the composite material, the stress is dispersed and transmitted to the load-bearing material by the deformation of the base material.

  Composite materials usually have a very high strength, but in most cases the strength is not isotropic, while it exhibits a high strength against stress in a direction parallel to the plane of the composite material. Thus, the strength against stress in the direction perpendicular to the plane is much smaller. Due to such characteristics, a multilayered composite material is likely to cause delamination. The delamination occurs because at least one layer of the composite material having a multilayer structure is peeled off from the previously joined layer, and as a result, voids are generated inside the composite material. This void is extremely difficult to detect and can lead to catastrophic failure without any prior notice as stress is repeatedly applied.

  Carbon nanotubes can be used as load bearing materials in composite materials. As explained above, a composite material is generally a material composed of two or more different types of component materials, usually a matrix that defines the overall shape of the composite material, and the interior of the composite material. And at least one load bearing material that determines the structure. Any of various known materials that have been used as the base material can be used as the base material of the composite material of the present invention (for example, Mel M. Schwartz (See “Composite Materials Handbook (2nd edition, published in 1992)”). Specific examples of some of the known base material materials include various thermosetting or thermoplastic resins (polymers), various metal materials, ceramic materials, cermet materials, and the like.

  Thermosetting resins useful as a base material include phthalic polyester resins, maleic polyester resins, vinyl ester resins, epoxy resins, phenol resins, cyanate resins, bismaleimide resins, nadic end caps. There is a nadic end-capped polyimide (for example, PMR-15). In addition, useful thermoplastic resins include polysulfone resins, polyamide resins, polycarbonate resins, polyethylene oxide resins, polysulfide resins, polyether-ether-ketone resins, polyether-sulfone resins, polyamide-imide resins, polyetherimide resins. , Polyimide resin, polyarylate resin, and liquid crystal polyester resin. In one preferred embodiment, epoxy resin is used as the base material.

  Examples of metal materials useful as a base material include various aluminum alloys such as “aluminum 6061”, “aluminum 2024”, and “aluminum 713”. Ceramic materials useful as a base material include glass ceramics such as lithium aluminosilicate, oxide ceramics such as alumina and mullite, nitride ceramics such as silicon nitride, and carbide ceramics such as silicon carbide. Thermic materials useful as a base material include carbide-based thermic (tungsten carbide, chromium carbide, titanium carbide, etc.), refractory thermic (tungsten-tria, barium-carbonate-nickel, etc.), chromium-alumina, nickel-magnesia And there is iron-zirconium carbide.

  The form of the load-bearing material composed of carbon nanotubes according to the present invention may be any of the various forms described in the present specification and various known forms. However, it is preferable to use fullerene nanotubes (ie, carbon nanotubes with molecular structural integrity). Some fullerene nanotubes have a shape in which a hemispherical fullerene cap is bonded to the end of a tube formed by joining single-layer continuous hexagonal graphene sheets without defects. In this case, those with hemispherical caps at both ends are sometimes called intrinsic single-wall fullerene nanotubes, and the nanotubes whose ends are blocked are cut or eroded. What removed the edge part may be called a single wall fullerene nanotube. Furthermore, a form in which a plurality of single-wall fullerene nanotubes are nested is called a multi-wall fullerene nanotube, and such fullerene nanotubes also exist. Multi-wall nanotubes (MWNTs) grown by the arc method are gradually approaching the ideals that can be called fullerenes, but their molecular structure is still imperfect. The MWNT grown by the arc method has considerable structural defects in the side wall portion of the multilayer structure, and the density of the structural defects reaches one or more of every 100 nm. In contrast, single wall carbon nanotubes produced by the laser / oven method described above are recognized to have molecular structural integrity. Accordingly, single wall carbon nanotubes produced by the laser / oven method become fullerene nanotubes, and carbon fibers formed from such carbon nanotubes become intrinsic fullerene fibers.

  Some single-walled fullerene nanotubes have metallic material characteristics (armchair type, that is, (n, n) form), while others have helical structure that does not have metallic material characteristics. There are also things. Any of these can be used in the form of a short tube-shaped molecule by cutting into an appropriate length. Short nanotubes (cut nanotubes) formed by cutting provide advantages that cannot be obtained by conventional techniques, such as strengthening and reinforcement on a molecular scale. On the other hand, when the length of the nanotube approaches the micron scale, the flexibility becomes large while having the characteristic of a tubular molecule having rigidity at the molecular scale.

A structure in which a plurality of carbon nanotubes are bundled is called a rope in this specification, but a rope made of up to about 10 ³ carbon nanotubes is also useful as a load-bearing material for a composite material. The carbon nanotube ropes produced by the method described above have a physical shape that entangles with each other to form many micron-scale loops, so between the ropes and between the rope and the base material. In addition, an interaction as if it was a magic tape (registered trademark) works, and at the molecular level, a structure as a bundle of highly rigid tubes is maintained.

Giant carbon nanotube fibers (fiber consisting of 10 multiple of more than ^six nanotubes) are also useful as strength materials of the composite material according to the present invention. As the giant fiber used as the load-bearing material, any of the above-described uniform continuous fiber and random fiber can be used. Furthermore, when ropes or fibers are used as load bearing materials, they may be cut into ropes or fibers of a desired length by the method described above, or ropes or fibers may be used. A felt-like shape in which fibers are entangled to form many loops may be used.

  According to the present invention, it is also conceivable to use a combination of two or more of the various forms of carbon nanotube materials described above. In that case, the materials may be mixed and blended in the same region in the base material, or the materials may be blended in separate regions in the base material. The form of carbon nanotube material used will be selected depending on the nature of the composite material and depending on what properties the composite material will ultimately have. Moreover, it is preferable that the carbon nanotube material to be used has been subjected to washing treatment and purification treatment by the method described above.

  The nanotube, rope, or fiber used for the composite material may be modified by the method described above. By applying the modification treatment to the end caps of the carbon nanotubes, the bonding state between the carbon nanotubes or the bonding state between the carbon nanotubes and the base material can be strengthened. In general, the sidewall portion of the intrinsic carbon nanotube has a completely uniform structure (ie, an array of carbon having a hexagonal lattice structure similar to the lattice structure of graphite), and therefore the sidewall By introducing defects in the portion to form a binding site, the bond adhesion characteristics of the base material to the material can be improved. As a specific example, boron atoms or the like may be introduced as impurities into the side wall portion. The defects formed in the wall portion thus formed serve as a binding site, and the interaction by the physical force or chemical force acting between the nanotube and the base material is strengthened. In addition, defects or binding sites formed in this way may affect the properties of the final composite material by promoting a chemical reaction between the nanotube and the matrix material. . In addition to introducing boron atoms, as described above, there is a method in which a part of the lattice of the carbon nanotube is replaced with boron nitride.

  The carbon nanotube according to the present invention may be combined with a fiber-shaped load-bearing material made of another organic material or inorganic material and used as a load-bearing material in a composite material. An example of an organic material that can be used for this purpose is cellulose. Examples of inorganic materials include carbon, glass (D-type, E-type, and S-type glasses), graphite, silicon oxide, carbon steel, aluminum oxide, beryllium, beryllium oxide, boron, boron carbide, boron nitride. , Chromium, copper, iron, nickel, silicon carbide, silicon nitride, alumina yarn with the product name “FP” manufactured by DuPont, and alumina-boria with the product name “Nextel” manufactured by 3M There are silica and zirconia-silica, zirconia and alumina, quartz, molybdenum, “Rene41”, trade name “Saffil HT” manufactured by ICI, stainless steel, titanium boride, tungsten, and zirconium oxide.

  As a method for producing the composite material according to the present invention, any of various known materials for combining a base material and a load-bearing material can be employed. Carbon nanotube materials include those in which individual carbon nanotubes are separated separately, and those in which a plurality of carbon nanotubes are bundled to form a rope, such as water and organic By dispersing in a liquid carrier such as a solvent, the base material can be easily blended into the material. The handling method when compounding the giant carbon nanotube fiber can be the same as the conventional general handling method when compounding the carbon fiber or the graphite fiber.

  The carbon nanotube-bearing material is uniformly mixed with the matrix material precursors (polymer solution, pre-fired ceramic particles, etc.) and then completed as a composite using conventional techniques. You may do it. In addition, a load-bearing layer or load-bearing component (for example, felt-like material, bucky paper, etc.) is once formed from a carbon / nanotube material, and the formed material is impregnated with a prepolymer solution to form a composite material. There is also a way to do it.

  It is also possible to improve the properties of conventional composite materials using a load bearing material made of carbon nanotubes. One specific example is a composite material in which a fiber material layer is impregnated with a matrix polymer material to integrate the fiber material and the matrix material. A well-known composite material of this type is, for example, a composite material formed by integrating a woven layer of graphite fiber with a base epoxy material. In this composite material, there is a method of blending a carbon nanotube rope or fiber which is entangled three-dimensionally and forms many loops only at the interface between the epoxy material and the graphite material. Thus, the resistance to delamination of the layered composite material composed of the epoxy material and the graphite material can be greatly improved. In addition, after the carbon nanotube material is dispersed in the epoxy material, the epoxy material may be impregnated (or the carbon nanotube material is preliminarily added to one of the reaction components of the epoxy material. May be mixed). Further, a carbon nanotube material dispersed in a liquid carrier may be applied to the graphite fiber layer every time it is laminated by an application method such as spraying.

  For example, single-walled fullerene nanotubes, such as (10,10) nanotubes, are unique to components that have not been used so far. In some cases, the single-walled fullerene / nanotube material is a macromolecular polymer similar to polypropylene, nylon, kevlar, and DNA, and may simply be considered a novel material. However, single-walled fullerene nanotubes have a diameter that is comparable to the diameter of a DNA double helix, but the rigidity against bending and the strength against tension are incomparably large. One of the properties representing the characteristics of a polymer that forms a long chain is a sustained distance (a movement distance required for the chain direction to substantially change under conditions of normal Brownian motion). For polypropylene, this persistence distance is only about 1 nm, and for DNA double helix it is about 50 nm. In contrast, a single (10,10) fullerene nanotube that exists in isolation has a sustained distance of 1000 nm or more. Therefore, if judged based on the sustained distance of normal polymer molecules used to form a continuous phase of a composite material, it can be said that fullerene nanotubes are pipes having sufficient rigidity.

  In addition, a single (10,10) fullerene nanotube that exists in isolation is very flexible when its length is expressed in microns. It becomes entangled with other nanotubes to form many loops. Two new possibilities for the internal structure of the composite material have been obtained by entanglement of the nanotubes and the formation of multiple loops. That is, (1) the matrix material forming the continuous phase enters these loops, so that the nanotubes are tightly “bonded” to the matrix material of the continuous phase on a submicron length scale. be able to. In addition, (2) by mixing and mixing nanotubes and a continuous phase matrix material before the matrix material hardens and shearing them, the loops are entangled in a more complex manner, and the tensile force is applied to the nanotubes. Can be added. Thereby, the toughness, strength, and resistance to delamination of the composite material containing entangled fullerene nanotubes can be improved.

Fullerenes such as C ₆₀ and C ₇₀ are known to be an effective adsorbent materials to better adsorb free radicals. Similarly, fullerene nanotubes such as (10,10) nanotubes also have the property of chemisorbing free radicals on their walls. Examples of free radicals that can be chemisorbed include methyl and phenyl groups. Methoxyl group, phenoxyl group, hydroxyl group, and so on. As in the case of fullerenes with low molecular weights, fullerenes and nanotubes rarely reduce the strength of the network structure due to chemical adsorption of free radicals. Only the radicals adsorbed on the surface of the fullerene are released, and the fullerene structure itself is kept intact). Therefore, when forming a composite material containing fullerene / nanotube, free radicals are generated by heating or photolysis by ultraviolet irradiation to the polymer material forming the continuous phase of the composite material. If a group is added, the fullerene nanotube and the polymer material can be covalently bonded. For example, azo bridges such as those contained in azo bisisobutyronitrile are very effective as radical sources that are activated by light irradiation to generate free radicals.

  The carbon fiber provided by the present invention has unprecedented unique characteristics, and can be used as a new reinforcing material for composite materials. For example, a composite material having anisotropy in which a fiber material and a polymer material are combined can be formed. For this purpose, for example, carbon nanotube fibers (for example, fibers formed of (n, n) SWNT) having metallic material properties are dispersed in a prepolymer solution (for example, polymethyl methacrylate), and externally. The prepolymer may be polymerized after an electric field is applied to align the nanotube fibers. Furthermore, it is also possible to form a conductive material by using carbon nanotubes having such metal material characteristics.

  The composite materials containing carbon nanotubes described above have a wide range of uses, and it is not possible to list all of them. However, if some of them are described in detail, first, graphite fiber and Kevlar The various uses for which high-strength fibers such as these are used can all be used for composite materials containing carbon nanotubes. More specifically, it can be used as a structural material for various vehicles such as passenger cars, trucks, railway vehicles, etc. and as a plate material for vehicle bodies. It can also be applied to tires. It can also be used as aircraft parts, for example, it can be used for airframes, stabilizers, wing surface materials, ladders, flaps, etc., and helicopters can be used for rotor blades, ladders, elevators, ailerons, spoilers. It can be applied to passenger doors, engine pods, and fuselage components. As for the spacecraft, it can be applied to rockets, spacecrafts, artificial satellites and the like. It can also be applied to rocket nozzles. Marine applications include ship hull, hovercraft, hydrofoil, sonar dome, antenna, float, buoy, mast, spar, deck room, fairing, tank, etc. In addition, sports equipment-related applications include golf carts, golf club shafts, surfboards, hangrider frames, kite throwing kites, hockey sticks, sailplanes, sailboards, ski poles, play equipment, fishing rods, skis And water skis, bows, arrows, rackets, pole vault sticks, skateboards, bats, helmets, bicycle frames, canoes, catamarans, oars, paddles, and various other items. Moreover, it can apply to a chair, a lamp | ramp, a table, and various other modern furniture as a use regarding furniture. Other uses include, for example, stringed instrument resonance plates, various lightweight protective equipment for body protection, vehicle protection, and article protection, tools such as hammer grips and ladders, biocompatible implants, artificial It can be applied to bones, various prostheses, electric circuit boards, and all kinds of pipes.

Specific Examples Some specific examples are provided below to provide a better understanding of the present invention. However, the scope of the present invention is not limited to the specific embodiments disclosed as specific examples below, and these are merely specific examples for explanation.
Specific Example 1 Oven / Laser Vaporization Process The apparatus used in the vaporization process of this example is the oven / laser vaporization apparatus described with reference to FIG. 1, which is described by Haufler et al., “Carbon Arc Generation of C”. ₆₀ "Mat. Res. Soc. Symp. Porc., Vol. 206, p. 627 (1991) and also in US Pat. No. 5,300,203. An Nd: YAG laser was used as the laser for generating the scanning laser beam. This laser beam is controlled by a motor-driven total reflection plate and focused on the surface of a metal-graphite composite target placed in a quartz tube, resulting in an irradiation spot diameter of 6-7 nm. It was set as follows. The scanning of the surface of the target with a laser beam was controlled by a computer so that the surface of the target was always kept smooth with no irregularities. The laser device was set to emit a pulse beam having a wavelength of 0.532 μm, and the energy of one pulse was set to 300 mJ. The pulse injection speed was set to 10 Hz, and the pulse duration was set to 10 nanoseconds (ns).

  The target is placed in a quartz tube with a diameter of 1 inch (about 25.4 mm) supported by a graphite rod, and after the inside of this quartz tube is first evacuated until its pressure drops to 10 mTorr. Argon was injected, and thereafter the argon pressure was maintained at 500 Torr. Also, the argon volume flow was set at 50 standard cubic centimeters per second (sccm). Since the diameter of the quartz tube is 1 inch, when the volume flow rate is this value, the flow rate of argon flowing through the quartz tube takes a value within the range of 0.5 to 10 cm / sec. Laminar flow. The quartz tube was placed in a high temperature furnace, and the maximum temperature of this high temperature furnace was set to 1200 ° C. This high-temperature heating furnace was a Lindberg furnace having a length of 12 inches, and the temperature was maintained at 1000 to 1200 ° C. during several experiments in this specific example 1. The target material vaporized by irradiating the laser is carried on the flowing argon from the vicinity of the vaporized target and deposited on the surface of the water-cooled collector. This water-cooled collector was made of copper, and was arranged on the downstream side of the target, just outside the heating furnace outlet.

  The target was formed by molding a composite material in which a plurality of component materials were uniformly mixed into a rod shape, and was manufactured according to the following three steps. (1) A paste prepared by mixing a high-purity metal material or metal oxide material with room temperature at the following ratio with powder graphite made by Carbone of America and carbon cement made by Dylon. Filled into a 0.5-inch cylindrical mold, (2) Mount the paste-filled mold on a Carvey hydrostatic press equipped with a heating plate, and apply a certain pressure to it. In this state, firing is performed at 130 ° C. for 4 to 5 hours, and (3) the fired rod (which becomes a rod shape because the molding mold has a cylindrical shape) is further flowed in a flowing argon atmosphere. Baked for 8 hours at 810 ° C. Each time the test was run, a new target was prepared, and the target was first maintained at 1200 ° C. in a flowing argon atmosphere. The time for maintaining this heated state was not constant, but in most cases, it was 12 hours. After maintaining the heating state in this way, the test work was started, and the test operation for the same target was repeated a plurality of times. When the test operation was repeated, the target was kept heated to 1200 ° C. for an additional 2 hours each time immediately before the start of each test operation.

  In this specific example, the types and concentrations of the metal material components in the mixed material forming the target were variously set as follows. Cobalt (1.0 atomic%), copper (0.6 atomic%), niobium (0.6 atomic%), nickel (0.6 atomic%), platinum (0.2 atomic%), combination of cobalt and nickel (each 0.6 atomic% / 0.6 atomic%) ), A combination of cobalt and platinum (0.6 atomic% / 0.2 atomic%, respectively), a combination of cobalt and copper (0.6 atomic% / 0.5 atomic%, respectively), and a combination of nickel and platinum (0.6 atomic% / 0.2, respectively) atom%). Most of the remaining components of the mixed material are graphite, and contain a small amount of carbon cement. Each target formed with these target materials was vaporized with a laser, and each time the soot adhered to the surface of the water-cooled collector was collected, and the soot was subjected to ultrasonic treatment. This sonication was carried out for 1 hour at room temperature and normal pressure by dispersing soot in a methanol solvent (other good solvents other than methanol include 1,2-dichloroethane, 1 -Bromo, 1,2-dichloroethane, N, N-dimethylformamide, etc.). The recovered products were each sonicated in methanol for 30-60 minutes, all with uniform exceptions, with one exception. The exception is a sample obtained by vaporizing and vapor-depositing a mixed material consisting of cobalt, nickel, and graphite. The vapor-deposited sample is rubbery and ultrasonicated in methanol for 2 hours. Even after the treatment, a small portion thereof remained without being sufficiently dispersed. The soot obtained as described above was then examined using a transmission electron microscope (JEOL 2010 type) having a beam energy of 100 keV.

  The target materials listed above include materials that contain only one type of group VIII transition metal as a metal component and materials that contain a combination of two types of group VIII transition metals. An experiment to evaluate a target (diameter 0.5 inch) made by molding the material into a rod shape was conducted using the test equipment described above, and the yield and quality of the produced single-walled carbon nanotubes were examined. . The presence of multi-walled carbon nanotubes in the reaction product was not observed when using targets made of any material. The yield tended to increase as the oven temperature increased, and this trend did not change until the upper limit temperature of the oven used (1200 ° C.). When the oven temperature is set to 1200 ° C, among the materials containing only one kind of metal as the metal component, the one containing nickel has the highest yield of single-walled carbon nanotubes and contains cobalt What followed was what it did. Those containing platinum produce only a small number of single-walled carbon nanotubes. In addition, in mixed materials in which only copper is mixed into graphite or mixed materials in which only niobium is mixed into graphite, single-layered carbon・ Nanotube formation was not observed. On the other hand, among the materials obtained by mixing two kinds of group VIII transition metals as catalyst metal components with graphite, the single-wall, carbon, and nanotube yields are the combination of cobalt / nickel and cobalt / platinum. Two combinations of the combinations were almost in line with each other, and the results were extracted from other combinations of catalytic metals. Each of these two combinations of metal components has a single-wall, carbon, and nanotube yield of 10 compared to a material that uses only one group VIII transition metal as the metal component. It turned out to be ~ 100 times. Further, it was found that the mixed material in which the nickel / platinum combination was mixed with graphite also had a higher yield of single-walled carbon nanotubes than the mixed material containing only one metal component. The mixed material in which the combination of cobalt / copper was mixed with graphite produced a small amount of single-walled carbon / nanotubes.

  In the case of using a mixed material in which the combination of cobalt / nickel is mixed with graphite, and in the case of using a mixed material in which the combination of cobalt / platinum is mixed in graphite, the product deposited on the surface of the water-cooled collector is not Appears like a sheet of rubbery material. The deposited material was carefully removed from the surface of the water-cooled collector and collected without being damaged. When a target made of a mixed material mixed with a cobalt / platinum combination is used, the yield of single-walled carbon nanotubes produced is 15% by weight based on the total carbon component vaporized from the target. The evaluation value was obtained. In addition, when a target made of a mixed material mixed with a cobalt / nickel combination is used, the yield of the produced single-walled carbon nanotubes should be 50% by weight or more based on the vaporized carbon component. I understood.

  The images shown in FIG. 15A to FIG. 15E are generated by vaporizing a target material in which cobalt and nickel are mixed in graphite (0.6 atomic% / 0.6 atomic%, respectively) at an oven temperature of 1200 ° C. It is an image of a transmission electron micrograph of a layer, a carbon, and a nanotube. FIG. 15A shows a medium-magnification image (scale bar indicates 100 nm). A bundle of a plurality of single-walled carbon nanotubes is formed almost everywhere. It can also be seen that these bundles are intertwined with other single-walled carbon nanotubes. FIG. 15B shows a high-magnification image of a single bundle in which a plurality of single-walled carbon nanotubes are bundled, and a plurality of single-layer carbons constituting this single bundle. -All the nanotubes extend substantially parallel to each other. These single-walled carbon nanotubes are about 1 nm in diameter, and the spacing between adjacent single-walled carbon nanotubes is almost the same as this. These single-walled, carbon, and nanotubes are attached to each other by van der Waals forces.

  In the image shown in FIG. 15C, a plurality of single-walled carbon / nanotube bundles overlap each other. From this image, a plurality of single-walled carbon nanotubes constituting the same bundle are It can be seen that they extend substantially parallel to each other. Furthermore, from this image, it can be seen that single-wall, carbon, and nanotube bundles overlap each other and that the bundle bends. FIG. 15D shows various forms of single-walled carbon-nanotube bundles that are bent at various angles and with various arcs. Further, since some of the bent portions of the bundles are bent at a relatively sharp angle, it is understood that the single-walled carbon nanotube bundle has high strength and flexibility. FIG. 15E shows a cross section of the bundle, which is composed of seven single-walled carbon nanotubes that extend substantially parallel to each other. When various carbon nanotubes such as single-walled carbon nanotubes are grown by the arc discharge method, it is generally observed that the surface of the grown nanotubes is covered with amorphous carbon. However, the transmission electron microscope images of FIGS. 15A-15E show that the carbon nanotubes are not covered by such amorphous carbon. Further, it can be seen from the images in FIGS. 15A to 15E that the overwhelming majority of the deposited material is single-walled carbon nanotubes. The yield of single-walled carbon nanotubes is estimated to be about 50% of the vaporized carbon component. It is estimated that the remaining 50% is mainly composed of various fullerenes such as multi-layer fullerenes (so-called fullerene onions) and / or amorphous carbon.

The transmission electron microscope images shown in FIGS. 15A to 15E are generated by using a target mixed with a cobalt / nickel combination as a catalyst metal and deposited on the surface of the water-cooled collector of the laser vaporizer shown in FIG. It is a carbon nanotube sample image which is a thing. In general, single-walled carbon nanotubes are bundled together to form a bundle, and the single-walled carbon nanotubes that make up one bundle are almost the full length of them. They are attached to each other by van der Waals forces and extend substantially parallel to each other. The appearance of bundles of single-walled carbon and nanotubes is similar to the structure of a “highway”, and single-walled carbon and nanotube bundles are like cross-connects on highways. In a random manner and connected to each other. Judging from the images shown in FIG. 15A to FIG. 15E, many single-walled carbon nanotubes already extend close to each other as shown in the images when landing on the surface of the low-temperature water-cooled collector. It seems that there is a high possibility that single-walled carbon nanotubes exist at a very high density in the gas phase. Still further, the single-walled carbon nanotubes are neatly aligned as shown in the images, indicating that the carbon nanotubes had a perimeter before they landed on the surface of the water-cooled collector. In addition, it is considered that there was almost no other form of carbon covering the surface of the carbon nanotube. Evidence that the growth of single-walled carbon nanotubes is not performed on the inner wall surface of the quartz tube, but in the gas phase, is evidence that the multi-wall carbon This has already been demonstrated in previous research papers on nanotubes. Guo et al., “Self-Assembly of Tubular Fullerens,” J. Phys. Chem., Vol. 99, p. 10694 (1995) and Saito et al., “Extension of Single-Wall Carbon. See Nanotubes via Formation of Small Particles Condensed Near An Evaporation Source, "Chem. Phys. Lett., Vol. 236, p. 419 (1995). In the experiments described above, the high yields of single-walled carbon nanotubes were particularly noteworthy because the yield of fullerene that could be dispersed in the solvent was Because there was about 10%. The majority of other carbons in the soot-like product were various giant fullerenes and various multi-layer fullerenes.
Specific Example 2 In this specific example, a laser vaporizer similar to the laser vaporizer described with reference to FIG. 1 is used to produce a long single-layer carbon-nanotube. Carbon nanotubes were produced. The laser vaporizer used is different from the laser vaporizer shown in FIG. 1 in that a tungsten wire is stretched across a quartz tube disposed in an oven so as to cross its inner diameter. The position where the tungsten wire was stretched was a position further 1 to 3 cm downstream from the downstream end of the target (from the end defining the vaporization surface of the target, 13 ~ 15 cm down). The argon flowing through the quartz tube was set at a pressure of 500 Torr, and the flow rate was set so that the flow rate inside the quartz tube was 1 cm / sec. The oven temperature was maintained at 1200 ° C. The target material was a carbon material mixed with 1-3 atom% of a group VIII transition element.

The laser output setting was the same as in Example 1, and laser irradiation was performed for 10 to 20 minutes. As a result, a teardrop-shaped deposit was formed on the tungsten wire, and the deposit grew to a size of 3 to 5 mm depending on the portion. The growth of this deposit seemed to grow eyelashes on the tungsten wire. When this deposited material was examined, a bundle consisting of millions of single-walled carbon nanotubes was formed.
Specific Example 3. Vaporization Step Using Two Laser Beams A rod-shaped target containing graphite as a main component was formed by the same method as that described with respect to Specific Example 1. The material is a mixture of graphite, graphite cement, and 1.2 atomic% metal mixed powder, and the composition of the metal mixed powder consists of 50 atomic% cobalt powder and 50 atomic% nickel powder. Met. This material was pressed to finish the target, which was done in the same manner as described for Example 1. The target manufactured as a graphite rod in this manner was mounted on a device having the same configuration as the device shown in FIG. A quartz tube equipped with a target manufactured as a graphite rod was placed in an oven, and the oven was heated to 1200 ° C. Argon gas from which water and oxygen were removed was flowed into the quartz tube by removing impurities using a catalyst, the pressure was about 500 Torr, and the flow rate was about 50 sccm (standard cubic centimeter per minute). However, the flow rate of the argon gas does not necessarily have to be this value. If a quartz tube having a diameter of 1 inch is used, the flow rate can be in the range of 1 to 500 sccm. A flow rate in the range of ~ 100 sccm is preferred. The first laser device was set to output a pulse beam having a wavelength of 0.532 μm, and the energy per pulse was set to 250 mJ. The pulse emission speed was 10 Hz, and the pulse duration was 5 to 10 ns. The second laser device was set to emit a pulse to the target when 50 ns had elapsed after the pulse emitted from the first laser device stopped. Further, the second laser device was set to emit a pulse beam having a wavelength of 1.064 μm, and the energy per pulse was set to 300 mJ. The pulse emission speed was 10 Hz, and the pulse duration was 5 to 10 ns. The first laser device sets the in-focus state so that an irradiation spot with a diameter of 5 mm is formed on the surface of the target, and the second laser device has a diameter 7 whose light intensity distribution forms a Gaussian distribution on the surface of the target. The in-focus state was set so that an irradiation spot of mm was formed. Further, the center of the irradiation spot of the first laser device and the center of the irradiation spot of the second laser device are made to coincide with each other on the surface of the target. When about one-tenth of a second has passed after the second laser device irradiates the target, the emission from the first laser device and the emission from the second laser device are repeated again and again. This process was repeated until the end of the vaporization step.

  Thus, the surface of the target was vaporized by laser irradiation to generate a sample, and the generated sample was collected downstream of the target. The production rate of this sample was about 30 mg / hr in terms of the weight of the untreated state (raw sample state) just collected. The product in the raw sample state consisted of a lump of single-walled carbon nanotubes extending in various directions. The bulk of the product in the state of the raw sample was composed of carbon fibers having a diameter of 10 to 20 nm and a length of 10 to 1000 μm.

About 2 mg of the product in the form of this raw sample was taken, put into 5 ml of methanol, and sonicated at room temperature for about 0.5 hour. A transmission electron microscope (TEM) analysis of the product thus subjected to ultrasonic treatment was conducted, and most of the product was a single-walled carbon nanotube rope. These ropes are bundles of 10-1000 single-walled carbons and nanotubes that extend close to each other (but branches in some places), and each rope has a substantially constant diameter over its entire length. It was. These ropes were 100 μm or more in length and were composed of a plurality of single-walled carbon nanotubes having the same diameter. In addition, about 70-90% by weight of the product after sonication was in the form of a rope. The ends of all of the single-walled carbon nanotubes constituting the single rope were all located within the range of 100 nm of the end portion of the rope. More than 99% of the single-walled carbon nanotubes that make up one rope extend uniformly and continuously over the entire length from one end of the rope to the other. It appeared to be free of defects.
Specific Example 4 A purification process for purifying a single-walled carbon nanotube sample to a purity of 99% or more By purifying a sample generated by the laser generation method described in US Patent Application No. 08 / 687,665 by the following method, A product with increased concentration of nanotubes was obtained. A single-walled / nanotube raw sample (estimated yield was 70%) generated by the laser generation method was put into a 2.6 M nitric acid aqueous solution and refluxed for 24 hours. This reflux was performed at a pressure of 1 atm and a temperature of 1200 ° C. The solution was then filtered using a Teflon filter paper with a pore size of 5 microns (using Millipore Type LS filter paper), and the single-walled nanotubes recovered by this filtration were converted to fresh nitric acid. The solution was poured into an aqueous solution (2.6 M) and refluxed for 24 hours. Subsequently, the solution is filtered again to collect a single-walled / nanotube sample. The sample collected by this filtration step is put into a solution in which NaOH is saturated in ethanol, and is allowed to stand at room temperature for 12 hours. And sonicated. Subsequently, the ethanol solution was filtered to recover a single-walled / nanotube sample, and the recovered sample was put into a 6 M HCl aqueous solution and neutralized by refluxing for 12 hours. Further, the acid solution was filtered to collect a nanotube sample, and the collected sample was baked in 1 atmosphere of H ₂ gas at 850 ° C. for 2 hours (into a 1 inch diameter quartz tube). H ₂ gas was flowed and the flow rate was 1-10 sccm). As a result, a purified sample of 70 mg was obtained. Detailed examination by TEM analysis, SEM analysis, and Raman spectroscopic analysis revealed that this purified sample had a purity of 99% or more. Further, most of the impurities contained slightly were nickel or cobalt particles confined in the carbon capsule.
Specific Example 5 Step of cutting SWNT to obtain short tubular carbon molecules By performing the filtration step and the firing step, the SWNT sample described in Example 1 was purified to obtain a bucky paper (thickness was about 100 μm). Met). The bucky paper was irradiated with a 2 GeV Au ⁺³³ ion beam for 100 minutes using a Texas A & M superconducting cyclotron device. The irradiated bucky paper has an infinite number of bullet holes with a size of 10 to 100 nm, and the average density of these holes is such that there is one for every 100 nm of nanotube length. there were. The bucky paper irradiated with the ion beam was put into a 2.6 M nitric acid aqueous solution and refluxed for 24 hours to remove amorphous carbon generated by fast ion irradiation. Subsequently, filtration was performed to collect the nanotubes, which were put into a solution of potassium hydroxide dissolved in ethanol and subjected to ultrasonic treatment for 12 hours. Furthermore, both ends of the cut nanotubes were closed by subjecting the nanotubes collected by filtration again to a firing treatment in vacuum at a temperature of 1100 ° C.

Subsequently, the sample was dispersed in toluene and subjected to ultrasonic treatment. When the tubular molecules thus obtained were examined using SEM and TEM, the average length was found to be about 50 to 60 nm.
Specific Example 6 Array Forming Step for Forming SWNT Array Using the method described above, about 10 ⁶ (10,10) nanotube molecules having a length of 50-60 nm were generated. These molecules were modified and a -SH group was added to one end of each molecule to form a SAM molecule array consisting of SWNT molecules on a gold-plated substrate. In this SAM molecular array, the longitudinal axes of the tubular SWNT molecules are aligned in parallel with each other, and a plane perpendicular to the longitudinal direction of the molecules is formed by the tips of the molecules.
Specific Example 7 Uniform Continuous Giant Carbon Fiber Growth Process Using the array described in Example 6, the device shown in FIGS. 6 and 7 can grow uniform continuous giant carbon fiber. it can. First, the tips of a plurality of nanotubes constituting the array are opened (the tips form a plane perpendicular to the longitudinal axis of the nanotubes). When a two-dimensional array of nanotubes is formed on the surface of a gold-plated substrate, the tips of the nanotubes can be opened by performing electrolytic erosion treatment in 0.1 M KOH aqueous solution using the two-dimensional array as a positive electrode. it can.

  Subsequently, Ni / Co metal clusters were formed on the open ends of each nanotube constituting the SAM nanotube array by vacuum deposition. In this case, the metal cluster is preferably formed to have a diameter of 1 nm, so that one nanotube is formed at the open end of each nanotube constituting the nanotube array. One Ni / Co cluster nanoparticle can be placed on each.

Subsequently, the nanotube array composed of the nanotubes whose upper end opening was closed with Ni / Co nanoparticles was subjected to a high-temperature treatment in a vacuum at 600 ° C. By this high-temperature treatment, carbon nanotubes and Ni / Co Eliminate everything else except the nanoparticles. After completing this high temperature treatment, when the ethylene gas begins to flow, the nanotubes begin to extend in the direction of their aligned longitudinal axes, forming a huge diameter carbon fiber. If most of the Ni / Co catalyst particles are deactivated, an electrochemical etching process opens the top of each nanotube, cleans the entire assembly of nanotubes and substrate again, and deposits as described above. The process may be performed again to place Ni / Co catalyst particles on top of the nanotubes and the array growth process may be resumed. By the above method, a uniform continuous carbon fiber having a diameter of about 1 μm can be obtained, which can be continuously wound around a winding roller and collected at room temperature.
Specific Example 8 Production Process of Fullerene Pipe and Fullerene Capsule First, a cylindrical target having a diameter of 2.5 cm and a length of 5 cm was attached to the apparatus to prepare single-wall fullerene nanotubes. This target is made of a material mainly composed of a carbon material (containing 2 atomic% of a mixed metal material in which cobalt and nickel are mixed at a ratio of 1: 1), and this target has a diameter of 10 Arranged in a cm fused silica tube. Argon was flowed into the fused silica tube (pressure was 500 Torr, flow rate was 2 cm sec ^-1 ), the fused silica tube was heated to 1100 ° C, and the target was centered on its cylindrical main axis. It was made to rotate. Two pulse laser beams (Nd: YAG, 1064 nm, energy 1 J per pulse, pulse injection speed 30 times / second, delay time 40 ns) on the outer surface of the rotating drum target The focus state is set so that an irradiation spot with a diameter of 7 mm is formed, and it is deflected to the left and right by computer control so that it can be scanned in the longitudinal direction of the drum target, and the incident angle to the target surface By changing so as to avoid the formation of deep depressions on the surface of the target. By this method, as much as 20 g of sample was obtained by continuous operation for 2 days. A high yield is an advantage of this method.

  The raw sample produced by the above apparatus was subsequently subjected to purification treatment. This purification treatment was performed by pouring the raw sample into an aqueous nitric acid solution and refluxing, followed by washing with an aqueous solution of pH = 10 in which Triton X-100 surfactant was dissolved. The net yield of the purified fullerene fiber obtained by purification by this method depends on the initial quality at the stage of the raw sample, but is usually a value in the range of 10 to 20% by weight. Fullerene fibers have the property that their sidewalls have molecular integrity, so they are not destroyed by the reflux process.

  The fullerene ropes obtained as described above were highly entangled with each other. These entangled fullerene ropes were found to form fullerene toroids (also called “crop circles”). This suggests that the fullerene ropes are endless. The fullerene ropes are connected to each other because when a laser / oven method is used to produce fullerene nanotubes, a high-yield growth process proceeds in an argon atmosphere. This is because Van der Waals forces act between the “growing” tip of the wing and the side of another fullerene rope. Since the growing fullerene rope tries to grow close to the side of the existing fullerene rope (guide rope), two fullerene ropes grow from opposite directions along the side of the same guide rope. When they come, the growing tips of the ropes collide, and the tips disappear when they connect. Since the growth of the rope is one-dimensional, this collision between the tips is inevitable.

In this way, end portions were formed in the fullerene rope group which is intertwined with each other and is almost endless. There are many methods for forming the end, from cutting the rope with scissors to driving high-speed gold ions having a relativistic velocity into the rope group. Then, for example, a method of cutting the rope by sonication in the presence of an acid having strong oxidizing properties such as H ₂ SO ₄ / HNO ₃ was adopted. The cavitation generated by ultrasonic waves causes local damage to the nanotubes located on the surface of the rope, and the activated nanotubes are subjected to chemical attack from highly oxidizing acids. . While the acid is attacking the nanotube, the nanotube is completely cut and, if cut, is eroded from the open ends formed by the cut and gradually shortens. At this time, since the temperature is not so high, the open end of the nanotube cannot be closed. Furthermore, if the nanotube located on the surface of the rope is cut, the underlying nanotube is exposed and the exposed nanotube is repeatedly damaged by cavitation, and finally the entire rope is cut. Is done. The rope was cut by the above method. In addition, by exposing the section of the nanotubes cut by cutting the rope in this way (cut nanotubes) to an acid having strong oxidizing properties, only the cut nanotubes with integrity at the molecular level can be obtained. At the same time, the cut nanotubes were chemically cleaned.

The length distribution of the cut nanotubes with open ends moves to the shorter side as the time of exposure to the acid increases. When the cut nanotubes were put into a solution in which concentrated sulfuric acid and concentrated nitric acid were mixed at a ratio of 3: 1 at a temperature of 70 ° C., the average shortening rate of the cut nanotubes was about 130 nm hr ⁻¹ . The average shortening speed in a solution (so-called “piranha”) in which concentrated sulfuric acid and a 30% aqueous hydrogen peroxide solution were mixed at a ratio of 4: 1 at a temperature of 70 ° C. was about 200 nm hr ⁻¹ . The rate of this erosion depends on the chiral index (n, m) of the nanotube, which means that every “armchair” nanotube (n = m) has a chemical property of “zigzag” nanotube (m = 0) The chemical properties of nanotubes with intermediate helical angles (n ≠ m) differ from their chemical properties, if not clearly, and if not so significantly. Because.

  When the cut fullerene / nanotube sample obtained as described above is put into water containing a surfactant such as sodium dodecyl sulfate or a nonionic surfactant such as Triton X-100, the surfactant is added. As a result, a stable colloidal suspension is obtained. The fullerene nanotubes in the suspension thus obtained were separated according to their length.

The cut nanotubes obtained by separation were attached to the surface of the graphite, and AFM image analysis was performed. Many nanotubes exist independently, but most of the nanotubes are fan- It turned out that they were sticking with each other due to their power. A nanotube having a length of 100 nm or more can be capped at its end with a hemispherical fullerene end cap. And a closed fullerene capsule can be formed by performing annealing treatment at a temperature of 1000 to 1200 ° C. in a vacuum.
Specific Example 9 Production Process and Purification Process of Fullerene Pipe and Fullerene Capsule Referring to FIGS. 16A to 16C, FIG. 16A is a SEM image of a SWNT felt sample in a raw state, and FIGS. 16B and 16C are the same SWNT felt sample. Is an SEM image of the purified sample. The raw sample is the starting material for the purification process, and it can be seen from these figures that the raw sample is too low quality, which confirms the effectiveness of the purification process described below. In this purification step, first, a raw sample (8.5 mg) was put into 1.2 liters of a 2.6 M nitric acid aqueous solution and refluxed for 45 hours. This aqueous solution was transferred to a test tube of a PTFE centrifuge, and the centrifuge was rotated for 2 hours while setting an acceleration of 2400 G. The supernatant acid was discarded, deionized water was added, and the solid component was suspended again by shaking vigorously, and the liquid component was discarded by centrifugation again to recover the solid component. Subsequently, 20 ml of Triton X-100 surfactant was added to 1.8 liters of water, and the solid components were put into an aqueous solution adjusted to pH 10 with sodium hydroxide and suspended again. This suspension was transferred to the reservoir of a tangential flow filtration system (using a Spectrum MiniKros Lab System, Laguna Hills, California, USA). The filter cartridge used at this time (M22M 600 0.1N filter cartridge manufactured by Spectrum) uses a hollow fiber of hybrid cellulose ester, the diameter of the hollow fiber is 0.6 mm, and the pore diameter is 200 nm, the entire surface area was 5600 cm ^2. Prepare 44 liters of 0.2 wt% Triton X-100 aqueous solution as a buffer solution, of which 34 liters used at the beginning are adjusted to basic (pH 10) with sodium hydroxide, and 10 liters used at the end are pH 7 It was adjusted to. The inlet pressure to the filter cartridge was maintained at 6 psi. In addition, the outflow rate was limited to 70 ml min ^-1 by a control valve installed at the outflow port. As a result of filtration with the above settings, a stable suspension of purified SWNT was obtained. The SEM image of this purified SWNT is usually as shown in FIG. 16B. The suspension was filtered to recover the solid components, thereby obtaining a paper-like material consisting of entangled SWNTs. This paper-like material looked like carbon paper in both appearance and feel. The SEM image in Fig. 16C shows the break when this "Bucky Paper" is broken. From this image, the direction of the fiber forming the SWNT rope is shown in the process of breaking the Bucky Paper. It can be seen that it is aligned to a considerable extent. The overall yield of this purified SWNT relative to the starting material too low quality crude SWNT was 9% by weight.

  FIG. 17 is a taping mode AFM image of a cut fullerene nanotube (pipe) in a stable colloidal suspension attached to the surface of highly oriented pyrolytic graphite (HOPG) using an electrodeposition method. The cut fullerene nanotubes in this image tend to extend at an angle of 120 ° C. with respect to each other. This is because the cut nanotubes extend along the direction of the graphite lattice underlying them. When the height of the cut nanotubes was measured by AFM, they were nanotubes with a diameter of 1 to 2 nm. About half of them existed alone, but the other half were joined together by van der Waals forces. , Found that they exist in a group. Such a cut nanotube is prepared through a two-stage process, and the two-stage process is a cutting process and a polishing process. A typical example is as follows. First, 40 ml of a mixed acid prepared by mixing concentrated sulfuric acid and concentrated nitric acid in a ratio of 3: 1 is placed in a test tube having a capacity of 100 ml, and “Bucky paper” (in FIG. (Shown) was subjected to ultrasonic treatment in a water bath at a temperature of 35 to 40 ° C. for 24 hours (this treatment was carried out using a B3-R type ultrasonic treatment device manufactured by Cole Palmer, (It was set at 55 kHz) and suspended. The resulting suspension is diluted with 200 ml of water and filtered using a filter membrane with a pore size of 100 nm (MilLipore VCTP membrane, Bedford, Massachusetts, USA) As a result, relatively long ones of the cut SWNT nanotubes were captured on the filter membrane. Furthermore, the captured nanotube was washed with 10 mM NaOH aqueous solution. Subsequently, the cut nanotubes thus obtained were subjected to a polishing treatment (chemical cleaning treatment). In this polishing treatment, first, the cut nanotubes are put into a solution in which concentrated sulfuric acid and a 30% aqueous solution of hydrogen peroxide are mixed at a ratio of 4: 1, and stirred at 70 ° C. for 30 minutes to be suspended. I let you. Subsequently, it was filtered again using a filter membrane having a pore size of 100 nm, washed, and dispersed in water containing 0.5% by weight of Triton X-100 surfactant. A suspension of concentrated nanotubes was prepared. On a newly cleaved HOPG substrate (using a substrate made by Advanced Ceramics, Cleveland, Ohio, USA), 20 μl of this nanotube suspension was dropped, and the droplet was added to the Vitron O-ring (outside The suspension was sealed by covering a stainless steel electrode on the O-ring, and a stable voltage of 1.1 V was applied for 6 minutes. Since the nanotubes are negatively charged when dispersed and suspended in water, the nanotubes are moved to the surface of the HOPG by the applied electric field. After the electrodeposition was completed in this manner, the HOPG surface with nanotubes attached thereto was mounted on a spin coating apparatus, and the surface was washed with methanol to remove water and Triton X-100 surfactant.

FIG. 18 is a graph showing the results of field flow fractionation (FFF) of a suspension in which “pipe” which is a cut fullerene nanotube is dispersed in water. A suspension in which a cut nanotube was dispersed at a concentration of 0.07 mg / mg in a 0.5% aqueous solution of Triton X-100 was prepared, and a cross-flow FFF device (LLC, Salt Lake City, Utah, USA) was prepared. 20 μl of this suspension was injected into an F-1000-FO type FF fractionation apparatus manufactured by the same manufacturer). The operating condition of this FFF apparatus was a 0.007% aqueous solution of Triton X-100 as a mobile phase, the flow rate was set to 2 ml min ^-1 , and the cross flow rate was set to 0.5 ml min ^-1 . The solid curve (left vertical axis) in FIG. 18A represents the amount of nanotubes to be eluted by the light scattering degree, that is, the turbidity (the light wavelength is 632.8 nm), and this value is shown at the start of elution. 5 is a curve showing the total injection volume of the eluent injected up to that point. The white circle (right vertical axis) is a plot of measured values of the radius of rotation of the nanotubes, and these measured values were measured using a 16-degree switching light scattering device (USA) DAWN DSP manufactured by Wyatt Technology, Santa Barbara, California, was used). FIG. 18B, FIG. 18C, and FIG. 18D are graphs showing the nanotube length distributions of the first fraction, the third fraction, and the fourth fraction of the FFF eluate, respectively. As shown in FIG. 17, the fullerene nanotubes in the suspension were deposited on the surface of the HOPG by electrodeposition, and were obtained using an AFM image.

FIG. 19 is an AFM image showing one fullerene / nanotube “pipe”, one spherical gold particle having a diameter of 10 nm, connected by a connecting chain. The nanotubes shown in this image are the ones attached to the surface of HOPG graphite by electrodeposition from a suspension of nanotubes and colloidal gold particles (made by Sigma Chemical). It is. Appearing as irregularly shaped patterns in this image are traces of residues of Triton X-100 surfactant residue used to stabilize the suspension. The connecting chain between the nanotube and the gold particle is constituted by an alkyl thiol chain covalently bonded to each of the open ends of the nanotube. The open ends of the nanotubes were corroded by acid in the previous processing step, so it is considered that many carboxyl groups were bonded, and these carboxyl groups were reacted with SOCl ₂ to react with each. Conversion was made to a carboxylic acid chloride corresponding to the carboxyl group. The modified nanotubes were subsequently exposed to NH ₂ — (CH ₂ ) ₁₆ —SH dissolved in toluene to form suitable linking chains. This linking chain is a binding site in which the thiol group in the linking chain is strongly covalently bonded to the gold particle. As a result of careful AFM image analysis, it was confirmed that most of the nanotubes subjected to this modification treatment have one gold particle bonded to at least one of both ends thereof.
Specific Example 10 Composite material containing carbon nanotubes
A suspension was prepared by dispersing 1 g of purified single-walled fullerene nanotubes in 10 g of an epoxy material having the trade name “Epon” dissolved in 1 liter of dichloroethane. A curing agent was added to this suspension, and the solvent content was removed with a vacuum rotary evaporator. The composite material composed of the fullerene nanotubes and the epoxy material thus obtained was cured by maintaining at 100 ° C. for 24 hours.

  Alternatively, it is possible to fabricate a composite material containing both carbon fiber and fullerene nanotubes. In this case, the suspension of dichloroethane, epoxy material, and nanotube described above is placed in a large container, and one or a plurality of uniform continuous carbon fibers or carbon fibers are woven. One or more carbon fiber tapes are passed through the suspension and impregnated with the suspension. Subsequently, the carbon fiber or carbon fiber tape impregnated with the suspension is wound around a form having a desired shape, and this is further processed by a method known in the carbon fiber-epoxy composite industry (about this). (See, for example, DL Chung, Carbon Fiber Composites (1994)). By curing in an autoclave, a composite material having excellent resistance to delamination is obtained. The fullerene nanotubes in this composite material serve to increase the strength of the epoxy material between the layers of the multi-layer carbon fiber layer. In addition to using carbon fiber as a material for the fabric tape layer, if the nanotube reinforcement compounded in an entangled state in the epoxy material phase is also made of carbon fiber, it will be excellent Composite material is obtained.

  From the above detailed description, it goes without saying that those skilled in the art can easily conceive modified or modified embodiments of the methods, apparatuses, compositions, and products disclosed herein. Rather, the scope of the claims is intended to cover such modified and modified embodiments.

1 is a schematic diagram of an apparatus for carrying out the present invention. 1 is a schematic diagram of an apparatus for practicing the present invention that uses two different laser pulses to vaporize a composite bar target. FIG. 2 is a transmission electron microscopy (TEM) spectrum of a purified single-walled carbon nanotube according to the present invention; FIG. 2 is a scanning electron microscopy (SEM) spectrum of purified single-walled carbon nanotubes according to the present invention; FIG. 3 is a Raman spectrum of a purified single-walled carbon nanotube according to the present invention; Schematically represents a portion of a uniform single-walled carbon nanotube molecular array according to the present invention; Schematically represents a portion of a non-uniform single-walled carbon nanotube molecular array according to the present invention; 1 schematically represents a fiber growth chamber device according to the invention; Schematically represents a fiber pressure equalization and collection zone according to the invention; A composite sequence according to the invention; A composite sequence according to the invention; A power transmission cable according to the invention; 2 schematically represents a bistable non-volatile nanoscale storage device according to the present invention; 12 is a graph representing an energy well corresponding to each bistable state of the memory bit of FIG. 11; 1 schematically represents a lithium ion secondary battery according to the present invention; An anode of a lithium ion battery according to the invention; Medium magnification transmission electron microscope image of single-walled carbon nanotubes; High magnification image of adjacent single-walled carbon nanotubes; High magnification image of adjacent single-walled carbon nanotubes; High magnification image of adjacent single-walled carbon nanotubes; A high magnification image of a cross section of seven adjacent single-walled carbon nanotubes; Scanning electron microscope (SEM) image of a crude single-wall fullerene nanotube felt; FIG. 17 is a SEM image of the single-wall fullerene nanotube felt material of FIG. 16 after purification; SEM image of substantial alignment of single-walled nanotube rope fibers obtained after tearing single-walled fullerene nanotube felt; An atomic force microscope (AFM) image of cut fullerene nanotubes deposited on highly oriented pyrolytic graphite; Is a graph of field flow fractionation (FFF) of a cut nanotube suspension; Represents the distribution of fullerene nanotube length measured by AFM for three collections; and FIG. 3 is a graph showing the nanotube length distribution of the first, third, and fourth fractions of the FFF eluate; A graph showing the nanotube length distribution of the first, third and fourth fractions of the FFF eluate; and An AFM image of a fullerene nanotube “pipe” connected to two 10 nanometer gold spheres is shown.

Claims (162)

A method of purifying a mixture comprising single-walled carbon nanotubes and amorphous carbon contaminants, the method comprising: (a) heating the mixture under oxidizing conditions sufficient to remove the amorphous carbon; and b) recovering a product comprising at least about 80% by weight of single-walled carbon nanotubes;
A method comprising the steps. The method of claim 1, wherein the oxidizing conditions comprise an aqueous solution of an inorganic oxidant. The method of claim 2 wherein said inorganic oxidant is selected from the group consisting of nitric acid, a mixture of sulfuric acid and hydrogen peroxide, potassium permanganate and mixtures thereof. The method of claim 2, wherein the aqueous solution is heated under reflux. The method according to claim 2, further comprising the step of subjecting the oxidation product of step (b) to a saponification treatment. The method of claim 5, wherein the saponification treatment comprises contacting the product with a basic solution. The method of claim 6 wherein the basic solution comprises sodium hydroxide. The method of claim 6, further comprising the step of neutralizing the saponified product with an acid. The method of claim 8, wherein the acid is hydrochloric acid. 9. The method of claim 8, further comprising the step of recovering a solid product from the saponification and neutralization product. The method of claim 10, wherein the product is recovered by a method selected from the group consisting of filtration, gravity sedimentation, chemical flocculation, and hydrocyclone separation. The method of claim 10, wherein the product is a two-dimensional product such as paper. The method of claim 12, further comprising the step of drying the product. The method of claim 13, wherein the product is dried at about 850 ° C in a hydrogen gas atmosphere. The method of claim 1, wherein the product comprises at least about 90 wt% single-walled carbon nanotubes. The method of claim 1, wherein the product comprises at least about 95 wt% single-walled carbon nanotubes. The method of claim 1, wherein the product comprises at least about 99% by weight of single-walled carbon nanotubes. A method for producing tubular carbon molecules having a length of about 5 to 500 nm, the method comprising: (a) cutting a single-walled nanotube-containing material to obtain a mixture of tubular carbon molecules having a length in the range of 5 to 500 nm. Making;
(B) isolating a portion of the molecule of substantially equal length from the tubular carbon molecule mixture. Said single-walled nanotube cutting into tubular carbon molecules,
(A) forming a substantially two-dimensional target containing single-walled nanotubes up to about 1 micron in length, and (b) irradiating the target with a high-energy beam of high-mass ions The method of claim 18 including the step of: 20. The method of claim 19, wherein the high energy beam is generated by a cyclotron and has an energy of about 0.1 to about 10 GeV. The method of claim 19, wherein the high mass ions have a mass greater than about 150 AMU. The method of claim 21, wherein the high mass ions are selected from the group consisting of gold, bismuth and uranium. The method of claim 22, wherein the high mass ion is Au ⁺³³ . Said single-walled nanotube cutting into tubular carbon molecules,
(A) producing a suspension of single-walled nanotubes in a medium;
19. The method of claim 18, comprising (b) sonicating the suspension with acoustic energy. 25. The method of claim 24, wherein the acoustic energy is generated by a device operating at 40KHz and having a power output of 20W. 19. The method of claim 18, wherein said single-walled nanotube cutting into tubular carbon molecules comprises refluxing the single-walled nanotube material in concentrated HNO3. 20. The method of claim 19, further comprising heating the tubular carbon molecule to form a hemispherical fullerene cap on at least one bottom surface thereof. 19. The method of claim 18, further comprising reacting the tubular carbon molecule with a material that provides at least one substituent on at least one of the bottom surfaces of the tubular carbon molecule at the reaction conditions. 27. The method of claim 26, further comprising reacting the tubular carbon molecule with a material that provides at least one substituent on at least one of the bottom surfaces of the tubular carbon molecule at the reaction conditions. The substituents are each independently hydrogen; alkyl, acyl, aryl, aralkyl, halogen; substituted or unsubstituted thiol; unsubstituted or substituted amino; hydroxy; and OR ′ (where R ′ is hydrogen, alkyl, acyl, Aryl, aralkyl, unsubstituted or substituted amino; selected from the group consisting of substituted or unsubstituted thiol; and halogen); and optionally interrupted by one or more heteroatoms, and optionally one or more ═O, or 30. The method of claim 28 or 29, selected from the group consisting of a linear or cyclic carbon chain wherein = S, hydroxy, aminoalkyl group, amino acid, or amino acid is substituted with 2-8 peptides. A method of forming a macroscopic molecular array of tubular carbon molecules, the method comprising: (a) at least about 10 ⁶ tubular carbon molecules of substantially the same length in the range of 50 to 500 nm;
(B) introducing a binding moiety into at least one bottom surface of the tubular carbon molecule;
(C) providing a substrate coated with a material to which the binding moiety binds; and (d) contacting the tubular carbon molecule containing the binding moiety with the substrate. 32. The method of claim 31, wherein the substrate is selected from the group consisting of gold, mercury and indium-tin-oxide. 33. The method of claim 32, wherein the linking moiety is selected from the group consisting of -S-, -S- (CH2) n-NH-, and -SiO3 (CH2) 3NH3. A method of forming a macroscopic molecular array of tubular carbon molecules, the method comprising: (a) providing a nanoscale array of microwells on a substrate;
(B) placing a metal catalyst in each of the microwells; and (c) feeding a hydrocarbon or CO source gas stream to the substrate under conditions that allow the growth of single-walled carbon nanotubes from each microwell. Including methods. 35. The method of claim 34, further comprising applying an electric field in the vicinity of the substrate to help align the nanotubes growing from the microwell. A method of forming a macroscopic molecular arrangement of tubular carbon molecules comprising: (a) a surface containing a single-walled carbon nanotube material that is (a) purified but entangled and relatively looped. Cause;
(B) placing the surface under oxidizing conditions sufficient to cause the broken short length nanotubes to protrude from the surface; and (c) aligning the nanotubes protruding from the surface in a direction generally perpendicular to the surface. And applying an electric field to the surface to cause fusion in the array by van der Waals interaction forces. 37. The method of claim 36, wherein the oxidizing conditions comprise heating the surface to about 500 ° C. in an atmosphere of oxygen and CO2. A method of forming a macroscopic molecular array of tubular carbon molecules, the method comprising assembling a sub-array of up to 10 ⁶ single-walled carbon nanotubes into a composite array. 39. The method of claim 38, wherein all the subarrays have the same type of nanotubes. 40. The method of claim 38, wherein the sub-array comprises heterogeneous nanotubes. 40. The method of claim 38, wherein the subsequence is made by the method of any one of claims 31, 34 or 36. A method of continuously growing macroscopic carbon fibers comprising at least about 10 ⁶ single-walled nanotubes in a generally parallel direction, the method comprising:
(A) producing a macroscopic molecular arrangement of at least about 10 ⁶ tubular carbon molecules in a generally parallel direction and having substantially the same length in the range of about 50 to about 500 nanometers;
(B) removing the hemispherical fullerene cap from the upper end of the tubular carbon molecule in the array;
(C) contacting the upper end of the tubular carbon molecule in the array with at least one catalytic metal;
(D) supplying a carbon gas source to the end of the array while applying local energy to the end of the array to heat the end to a temperature in the range of about 500 ° C. or about 1300 ° C .; And (e) a method comprising a step of continuously collecting growing carbon fibers. 43. The method of claim 42, wherein the fullerene cap is removed by heating in an oxidizing atmosphere. 44. The method of claim 43, wherein the oxidizing atmosphere comprises an aqueous or vapor phase etching with nitric acid at a temperature of about 500 ° C. in an atmosphere of oxygen and CO2. 43. The method of claim 42, wherein the catalytic metal is selected from the group consisting of Group VIII transition metals, Group VI transition metals, lanthanide series metals, actinide series metals, and mixtures thereof. 46. The method of claim 45, wherein the catalytic metal is selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, and Pt. 47. The method of claim 46, wherein the catalytic metal is selected from the group consisting of Fe, Ni and Co and mixtures thereof. 46. The method of claim 45, wherein the catalytic metal is selected from the group consisting of Cr, Mo, and W. 43. The method of claim 42, wherein the catalytic metal is placed on each nanotube in situ as a metal atom cluster. 50. The method of claim 49, wherein the metal atom cluster has from about 10 to about 200 metal atoms. 43. The method of claim 42, wherein the catalytic metal is loaded as preformed nanoparticles. 52. The method of claim 51, wherein the catalytic metal is Mo. 43. The method of claim 42, wherein the catalytic metal is placed in the form of a metal precursor selected from the group consisting of salts, oxides and complexes of the metal. 43. The method of claim 42, wherein the catalytic metal is deposited by evaporating metal atoms and condensing and fusing it to the open ends of the nanotubes. 55. The method of claim 54, wherein the evaporation is performed by heating the wire (s) containing the catalytic metal. 55. The method of claim 54, wherein the evaporation is performed by molecular beam evaporation. 43. The method of claim 42, wherein the carbon gas source is selected from the group consisting of hydrocarbons and hydrogen monoxide. 58. The method of claim 57, wherein said hydrocarbon is selected from the group consisting of alkyl having 1 to 7 carbon atoms, acyl, aryl and aralkyl. 59. The method of claim 58, wherein the hydrocarbon is methane, ethane, ethylene, acetylene, acetone, propane, propylene and mixtures thereof. 43. The method of claim 42, wherein the local energy is provided by a laser beam. 43. The method of claim 42, wherein the local energy is provided by a source selected from the group consisting of a microwave generator, an R-F coil and a solar concentrator. 43. The method of claim 42, wherein the end is heated to a temperature in the range of about 900 ° C to about 1100 ° C. A material composition comprising at least about 80 wt% single-walled carbon nanotubes. 64. The composition of claim 63, comprising at least about 90% by weight single-walled carbon nanotubes. 64. The composition of claim 63, comprising at least about 95% by weight single-walled carbon nanotubes. 64. The composition of claim 63, comprising at least about 99% by weight single-walled carbon nanotubes. A substantially two-dimensional article comprising at least about 80 wt% single-walled carbon nanotubes. 68. The article of claim 67, comprising at least about 90% by weight of single-walled nanotubes. 68. The article of claim 67, comprising at least about 95% by weight single-walled nanotubes. 68. The article of claim 67, comprising at least about 99% by weight of single-walled nanotubes. 68. The article of claim 67 in the form of a paper-like material. Tubular carbon molecules having the following structure:
here,
Is a substantially defect-free tubular graphene sheet (optionally doped with non-carbon atoms) having about 10 ² to 10 ⁶ carbon atoms;

here,
Is a hemispherical fullerene cap having at least six pentagons and the remaining hexagons;
n is a number from 0 to 30; and R, R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently hydrogen; alkyl, acyl, aryl, aralkyl, halogen, substituted or unsubstituted thiol , Unsubstituted or substituted amino, hydroxy, and OR ′ (wherein R ′ is selected from the group consisting of hydrogen, alkyl, acyl, aryl, aralkyl, unsubstituted or substituted amino, substituted or unsubstituted thiol; and halogen) And optionally a line where one or more heteroatoms are interrupted and optionally one or more ═O or ═S, hydroxy, aminoalkyl groups, amino acids, or amino acids are replaced with 2-8 peptides Can be selected from the group consisting of linear or cyclic carbon chains. 75. The molecule of claim 72, wherein the graphene sheet has a structure corresponding to (n, n) single-walled carbon nanotubes. 75. The molecule of claim 72, wherein the molecule has a length of about 5 to about 1000 nm. 75. The molecule of claim 74, wherein the molecule has a length of about 5 to about 500 nm. 75. The molecule of claim 72, wherein n is 0-12. 75. The molecule of claim 72, further comprising at least one endohedral species. 78. The molecule of claim 77, wherein said endohedral species is selected from the group consisting of metal atoms, fullerene molecules, other small molecules, and mixtures thereof. 79. A molecule according to claim 78 comprising (10, 10) single-walled nanotubes containing at least one endohedral species selected from the group consisting of C60, C70 or mixtures thereof. 80. The molecule of claim 79, wherein said C60 or C70 further comprises an endohedral substituent selected from the group consisting of metal atoms and metal compounds. A macroscopic molecular array comprising at least about 10 ⁶ single-walled carbon nanotubes in a substantially parallel state and having substantially the same length in the range of about 5 to about 500 nanometers. 82. The array of claim 81, wherein the nanotubes are of the same type. 83. The array of claim 82, wherein the nanotubes are of (n, n) type. 84. The array of claim 83, wherein the nanotubes are of (10,10) type. 84. The array of claim 83, wherein the nanotubes are of (m, n) type. 92. The array of claim 81, wherein the nanotubes have various types. 82. The array of claim 81 further comprising a substrate attached to one end of the array and oriented substantially perpendicular to the nanotubes in the array. 88. The array of claim 87, wherein the substrate is a bucky paper surface. 88. The arrangement of claim 87, wherein the substrate is a metal layer selected from the group consisting of gold, mercury and indium-tin-oxide. 87. The array of claim 86, wherein the central portion of the nanotube is of (n, n) type and the outer portion of the nanotube is of (m, n) type. A macroscopic carbon fiber comprising at least about 10 ⁶ single-walled carbon nanotubes in a generally parallel state. 92. The fiber of claim 91, comprising at least about 10 < ⁹ > single-walled carbon nanotubes. 92. A composite fiber comprising a number of the fibers of claim 91. 94. A molecular template array of continuous length carbon fibers comprising the fiber segments of claim 91. 92. The fiber of claim 91, having a length of at least 1 millimeter. 92. The fiber of claim 91, wherein a majority of the nanotubes are of the (n, n) type. 92. The fiber of claim 91, wherein not all of said nanotubes are of the same type. 92. A composite article of manufacture comprising a matrix material selected from the group consisting of metals, polymers, ceramics and cermets, wherein the matrix is embedded in the carbon fiber in an amount that enhances properties at least in part. 99. The composite article of claim 98, wherein the property is structural, mechanical, electrical, chemical, optical, or biological. 99. A high voltage power transmission cable wherein the at least one conductor comprises continuous carbon fiber according to claim 96. 101. The power transmission cable according to claim 100, wherein both the center conductor and the coaxially arranged outer conductor are made of carbon fiber, and an insulating layer is provided therebetween. 102. The power transmission cable according to claim 101, wherein the insulating layer is a gap. 102. The power transmission of claim 101, wherein said insulating layer comprises a material selected from the group consisting of insulating carbon fibers made from (m, n) type carbon nanotubes, insulating BN fibers made from hexaboron nitride nanotubes, and mixtures thereof. cable. 82. A solar cell for converting broad-spectrum light energy into current, comprising the molecular arrangement of claim 81 as a photon collector. 105. The solar cell of claim 104, further comprising a photoactive dye coupled to the top end of the nanotubes in the array. 78. A bistable non-volatile memory bit comprising the end-loaded tubular carbon molecule of claim 77. 107. The memory bit of claim 106, wherein the tubular carbon molecule is comprised of (10,10) type nanotubes and the endohedral species is a C60 or C70 fullerene molecule. 107. A bistable non-volatile memory device comprising the memory bit of claim 106, means for writing the bit, and means for reading the bit. 109. The nanocircuit element, wherein the means for writing comprises a nanocircuit element that is used to direct a positive or negative voltage pulse to the bit to transition the end-hedral species from a first end to a second end of the bit. Memory devices. Said means for reading said bits;
(A) a first nanocircuit element that is biased relative to a first voltage (VRead) and is spaced from the read end of the bit to form a first gap therebetween; and (b) A second nanocircuit element that is biased with respect to ground voltage (VG) and used to form a second gap spaced from the read end of the bit, and thereby the first and first 109. The memory device of claim 108, wherein the presence of the endohedral species is clearly recognized by the presence of a current through two gaps. 82. A microporous anode for electrochemical cells comprising the molecular arrangement of claim 81. 111. A lithium ion secondary battery comprising the anode of claim 111, a cathode comprising LiCoO2, and an aprotic organic electrolyte, wherein a lithium fullerene insertion compound (FIC) is produced at the anode under charging conditions. An apparatus for generating continuous macroscopic carbon fibers from a macromolecular molecular array comprising at least about 10 ⁶ single-walled carbon nanotubes and having a catalytic metal mounted on the open ends of the nanotubes, the apparatus comprising:
(A) means for locally heating only the open ends of the nanotubes in the template array within the growth and anneal zone to a temperature in the range of about 500 ° C to about 1300 ° C;
(B) means for supplying a carbon-containing source gas to the growth and annealing zone of the nanotube in the template array that is in direct contact with the heated open end; and (c) the growing open end of the fiber is grown and An apparatus comprising means for continuously removing growing carbon fibers from the growth and annealing zone while remaining within the annealing zone. 114. The apparatus of claim 113, wherein the local heating means comprises a laser. 114. The apparatus of claim 113, wherein the apparatus is sealed in a growth chamber maintained in a vacuum by an evacuation means. 116. The apparatus of claim 115, further comprising a vacuum feed lock zone and a take-up roll through which the continuously produced carbon fiber passes under atmospheric pressure. (A) a matrix; and (b) a composite material comprising a carbon nanotube material embedded in the matrix. 118. The composite material of claim 117, wherein the matrix comprises a polymer. 119. The composite material of claim 118, wherein the polymer comprises a thermosetting polymer. 120. The composite material of claim 119, wherein the thermosetting polymer is selected from the group consisting of phthalic / maleic polyesters, vinyl esters, epoxies, phenolic resins, cyanates, bismaleimides, and nad end-capped polyimides. 119. The composite material of claim 118, wherein the polymer comprises a thermoplastic polymer. 122. The thermoplastic polymer is selected from the group consisting of polysulfone, polyamide, polycarbonate, polyphenylene oxide, polysulfide, polyetheretherketone, polyethersulfone, polyamideimide, polyetherimide, polyimide, polyarylate, and liquid crystal polyester. The composite material described. 118. The composite material of claim 117, wherein the matrix comprises a metal. 118. The composite material of claim 117, wherein the matrix comprises a ceramic. 118. The composite material of claim 117, wherein the matrix comprises cermet. 118. The composite material of claim 117, wherein the carbon nanotube material comprises tubular carbon nanotube molecules. 118. The composite material of claim 117, wherein said carbon nanotube material comprises up to about 10 < ³ > SWNT ropes. 118. The composite material of claim 117, wherein said carbon nanotube material comprises more than 10 < ⁶ > SWNT fibers. 129. The composite material of claim 126, 127, or 128, further comprising an auxiliary fiber material. 129. The composite material of claim 126, 127, or 128, wherein the carbon nanotube material is modified to interact with the matrix material. (A) preparing a matrix material precursor;
(B) combining a carbon nanotube material with the matrix material precursor; and (c) a method of producing a carbon nanotube-containing composite material comprising forming the composite material. 132. The method of claim 131, wherein the carbon nanotube material is combined with the matrix material precursor prior to the forming step. 132. The method of claim 131, wherein the carbon nanotube material is combined with the matrix material precursor during the forming step. 132. The method of claim 131, wherein the carbon nanotube material is combined with the matrix material precursor immediately after the forming step. 132. The method of claim 131, wherein the matrix material precursor is flowed around a pre-former of the carbon nanotube material. (A) preparing an assembly of fiber materials;
(B) adding the carbon nanotube material to the fiber material; and (c) adding a matrix material precursor to the carbon nanotube material and the fiber material. 137. The method of claim 136, wherein the fibrous material is arranged in a two-dimensional sheet and a portion of the carbon nanotube material is oriented in a direction other than parallel to the sheet. 138. The method of claim 131 or 136, wherein the carbon nanotube material comprises tubular carbon nanotube molecules. 138. The method of claim 131 or 136, wherein the carbon nanotube material comprises up to about 10 < ³ > SWNT ropes. 138. The method of claim 131 or 136, wherein the carbon nanotube material comprises more than 10 < ⁶ > SWNT fibers. A three-dimensional structure that self-assembles from induced single-walled carbon nanotube molecules, and includes a plurality of multifunctional single-walled carbon nanotubes assembled in the three-dimensional structure. 142. The three-dimensional structure according to claim 141, wherein the single-walled carbon nanotube has a multifunctional derivative on its end cap. 142. The three-dimensional structure according to claim 141, wherein the single-walled carbon nanotube has multifunctional derivatives at many positions on the single-walled carbon nanotube. 142. The three-dimensional structure of claim 141, wherein the single-walled carbon nanotubes are assembled as a result of van der Waals attraction. 142. The three-dimensional structure according to claim 141, having electromagnetic properties. 142. The three-dimensional structure of claim 141, wherein the electromagnetic property is measured functionally by a specific agent. 142. The three-dimensional structure of claim 141, which is symmetrical. 142. The three-dimensional structure of claim 141, which is not symmetrical. 142. The three-dimensional structure according to claim 141, having biological properties. The three-dimensional structure according to claim 149, which acts as a catalyst for a biochemical reaction. The three-dimensional structure according to claim 149, which interacts with a biological tissue. 149. The three-dimensional structure according to claim 149, which acts as a drug for interacting with the function of a biological system. A light harvesting antenna comprising at least one single-walled carbon nanotube conductive element, wherein the at least one nanotube has a length selected for a desired current level and a desired voltage level. 154. The light collecting antenna of claim 153, wherein said at least one single-walled carbon nanotube forms a Schottky barrier. 154. The light collection antenna array of claim 153. 165. The light collection antenna array of claim 155, wherein the array is formed by self-assembly. A molecular electronic component comprising at least one single-walled carbon nanotube. The molecular electronics component is a bridge circuit for providing full-wave rectification, and the bridge circuit includes:
4 single-walled carbon nanotubes, each of the four single-walled carbon nanotubes forming one side of a square and bonded to two of four buckyballs, and each of the four bakeyballs is 158. The molecular electronics component of claim 157 disposed at a corner of a square. 159. The bridge circuit of claim 158, wherein the bakey ball and single-walled carbon nanotube are derived to functionally contain a specific binder. 158. The molecular electronics component of claim 157, which is a fullerene diode. Nanoscale manipulator comprising at least one single-walled carbon nanotube. The nanoscale manipulator according to claim 161, which is nanoforcepts.