JP2009538363A - Polymer materials incorporating carbon nanostructures and their fabrication methods - Google Patents

Abstract

  The present invention relates to a novel composite material in which carbon nanospheres are introduced into a polymer material. The polymeric material can be any polymeric or polymerizable material that has an affinity for the graphite material. Carbon nanospheres are hollow graphite-like nanoparticles. Carbon nanospheres can be produced from carbon precursors using template nanoparticles. The unique size, shape, and electrical properties of carbon nanospheres provide advantageous properties for composite materials incorporating these nanomaterials.

Description

  The present invention generally relates to a polymer material into which a carbon nanomaterial is introduced. In particular, the present invention relates to a polymer material into which carbon nanospheres are introduced.

  Carbon materials have been used as high performance and functional materials in various fields. Graphite is a well-known carbon material that has important properties such as electrical conductivity and inertness. Over the past decade, researchers have learned to create graphite structures on the nanometer scale. The most extensively studied and understood graphite nanostructure is the carbon nanotube. Recently, researchers have developed other methods for making other carbon nanostructures such as carbon “nano onions”, “nano horns”, “nano beads”, “nano fibers”, and the like.

  Some of these materials have been used to make composite materials by introducing nanostructures into polymeric materials. Most of these attempts have attempted to introduce single-walled and multi-walled nanotubes into the polymer. The use of carbon nanotubes as a filler material in a polymer will have the advantage of increasing the strength of the composite material and imparting electrical conductivity to the composite material.

US Pat. No. 6,689,835 US patent application Ser. No. 11 / 539,120, filed Oct. 5, 2006, entitled “Carbon Nanorings Manufactured From Templating Nanoparticulars”. US patent application Ser. No. 11 / 539,042, entitled “Carbon Nanostructured Manufacture From Catalytic Templating Nanoparticulates”, accepted on October 5, 2006. Han et al., “Simple Solid-Phase Synthesis of Hollow Graphitic Nanoparticles and their Applied Electrode to the Solid Solid-Phase Synthesis of Hollow Graphite-like Nanoparticles and Their Direct Application to Direct Methanol Fuel Cell Electrodes”. ”Advance Material (Adv. Mater). 2003, 15. No. 22 November 17

  However, it has proven very difficult to introduce carbon nanotubes into polymeric materials. The fibrous shape of carbon nanotubes, combined with their small size, makes it difficult to disperse uniformly in the polymer. In applications where electrical conductivity is required, the amount of carbon nanotubes needed to provide a significant reduction in electrical resistance is not costly in most applications.

  The present invention relates to a novel composite material in which a carbon nanomaterial is introduced into a polymer material. The carbon nanomaterial includes a carbon nanostructure that imparts a novel property to the polymer composite material. In one embodiment of the invention, the carbon nanostructure introduced into the polymeric material is a carbon nanosphere. Typically, carbon nanospheres have multiple walls of graphite that generally delimit round hollow nanoparticles.

  Various sizes of nanospheres can be made. In one embodiment, the diameter ranges from about 2 nm to about 500 nm, more preferably from about 5 nm to about 250 nm, and most preferably from about 10 nm to about 150 nm. The inner diameter of the nanosphere depends on the outer diameter of the nanosphere and the wall thickness. The inner diameter (ie, the diameter of the hollow portion) is typically between about 0.5 nm and about 300 nm, more preferably between about 2 nm and about 200 nm, and most preferably between about 5 nm and about 100 nm.

  In some cases, the carbon nanomaterial may be treated to create a nanomaterial that is more easily dispersed in the polymeric material and / or to remove functional groups (eg, acidic groups) from its surface. Is possible. In one embodiment, the carboxylic acid and other oxidizing functional groups are removed with a base to neutralize. In another embodiment, the dispersibility of the nanomaterial is improved by heat treatment of the material after it has been purified by an oxidizing agent.

  The polymer material used to make the composite material may be any polymer or polymerizable material that is compatible with the graphite material. Examples of polymers include polyamines, polyacrylates, polybutadiene, polybutylene, polyethylene, chlorinated polyethylene, ethylene vinyl alcohol, fluoropolymers, ionomers, polymethylpentene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride. , Condensation polymer, polyamide, polyamideimide, polyaryletherketone, polycarbonate, polyketone, polyester, polyetheretherketone, polyetherimide, polyethersulfone, polyimide, polyphenyleneoxide, polyphenylenesulfide, polyphthalamide, polyphthalimide , Polysulfone, polyarylsulfone, allyl resin, melamine resin, phenol formaldehyde resin, liquid crystal polymer, polyolefin Including emissions, silicone, polyurethane, epoxy, cellulosic polymers, combinations thereof, derivatives thereof or any copolymer of the above.

  The carbon nanospheres are in the range of about 0.1% to about 70%, more preferably in the range of about 0.5% to about 50%, most preferably about 1.0% by weight of the composite material. To about 30% by weight with the polymeric material. Carbon nanospheres can be added alone or in combination with other graphite materials to impart conductive performance to the composite material. To provide electrical conductivity, it is desirable to add about 3 wt% or more, more preferably about 10 wt% or more, and most preferably about 15 wt% or more of carbon nanospheres in the composite material.

  Any known method can be used as a method of making the composite material of the present invention. For example, the polymer material pellets and powder and the required amount of carbon nanospheres may be dry blended or wet blended and then mixed with a roll kneader under heating, or supplied to an extruder and extruded as a rope. It may be cut into pellets. On the other hand, the carbon nanospheres can be blended in a liquid medium as a solution or as a resin dispersion. If a thermoset polymerizable material is used, it can be mixed with the monomer or oligomer using any known method appropriate for that particular resin.

  Compared to other nanomaterials, especially nanotubes that are in a fibrous form, nanospheres are much easier to disperse in polymers or polymerizable materials due to their more spherical shape. For this reason, the nanospheres can be more easily dispersed like a particulate filler rather than a fibrous material. Typically, fibrous materials are difficult to disperse compared to particles, and much greater shear forces are required to ensure good dispersibility. In contrast, nanospheres can be blended with polymeric and polymerizable materials using low shear forces. The use of low shear forces in nanosphere blends reduces the likelihood of degrading the graphite material and the polymeric material in which it is dispersed.

  Any known method and / or material suitable for application to graphitic carbon can be used to improve the dispersion of nanospheres in the polymeric material. Further, any known method such as extrusion molding, blow molding, injection molding, or press molding can be used as a method of molding into a desired shape.

  The composite material of the present invention is expected to have beneficial properties derived from the unique shape, chemistry, and other aspects of the carbon nanospheres introduced therein. In particular, it has been found that carbon nanospheres can significantly reduce the electrical resistance of many macromolecules over comparable amounts of carbon nanotubes and carbon black. For example, about 16% by weight carbon black or 7% by weight carbon nanotubes in a polymeric material can achieve the required low electrical resistance value, while achieving the same required low electrical resistance value. The amount of carbon nanosphere required is surprisingly only about 3% by weight.

  These and other advantages and aspects of the present invention will become more fully apparent from the following description and the appended claims.

  To further clarify the above and other advantages and aspects of the present invention, a more detailed description of the invention will be presented with reference to specific embodiments of the invention illustrated in the accompanying drawings. Let's go. These figures only represent typical embodiments of the invention and should not be considered as limiting its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

I. Ingredients used to make the composite material The inventive polymer composite material comprises a mixture of polymer material and carbon nanomaterial. Carbon nanomaterials include carbon nanospheres that impart new properties such as low electrical resistance to composite materials. In some cases, the polymer composite material may include other additives such as fillers or other carbon nanomaterials. For the purposes of the present invention, the term nanosphere includes graphite-like hollow particles or spheres having a regular or irregular profile.

A. Polymeric Material Any polymeric material that is or is made compatible with the graphite material may be used in the novel composite material of the present invention. The polymeric material may be a synthetic, natural, or modified natural polymer or resin. Suitable polymeric materials include thermosetting and thermoplastic polymers, and / or polymerizable materials.

  Suitable polymeric materials that can be utilized in the composite materials of the present invention include the following polymers (and / or polymerizable materials selected to form one or more of the following polymers): Polyamine, polyacrylic ester, polybutadiene, polybutylene, polyethylene, chlorinated polyethylene, ethylene vinyl alcohol, fluorine polymer, ionomer, polymethylpentene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, condensation polymer, polyamide , Polyamideimide, Polyaryletherketone, Polycarbonate, Polyketone, Polyester, Polyetheretherketone, Polyetherimide, Polyethersulfone, Polyimide, Polyphenylene oxide, Polyphenylene sulfide, Polyphthal Amides, polyphthalimides, polysulfones, polyarylsulfones, allyl resins, melamine resins, phenol formaldehyde resins, liquid crystal polymers, polyolefins, silicones, polyurethanes, epoxies, cellulosic polymers, combinations thereof, derivatives thereof, or the above Any copolymer is included.

  The polymeric material may be a thermoplastic polymer that is mixed with the carbon nanospheres after heating. On the other hand, a thermosetting polymer can also be used. Typically, the thermosetting polymer is supplied as one or more polymerizable monomers or oligomers, which are then mixed with carbon nanospheres and polymerized to form a composite material.

  Those skilled in the art are familiar with monomers and / or oligomers that can be used to form the macromolecules described above. For example, polyurethanes are derived from the reaction of isocyanate groups with hydroxyl groups; polyureas are derived from the reaction of isocyanates with amines; silicones can be derived from hydrolysis of silanes and / or siloxanes, and so on. The present invention also includes copolymers having one or more polymeric blocks as described above. Additional polymers and polymerizable materials are disclosed in US Pat.

  Examples of suitable thermoplastic polymerizable materials include acrylonitrile-butadiene-styrene, acrylonitrile-ethylene / propylene-styrene, methyl methacrylate-butadiene-styrene, acrylonitrile-butadiene-methyl methacrylate-styrene, acrylonitrile-acrylic acid. n-butyl-styrene, rubber-modified polystyrene (impact polystyrene), polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polyvinyl chloride, cellulose acetate, polyamide, polyester, polyacrylonitrile, polycarbonate, polyphenylene oxide, polyketone, polysulfone , Polyphenylene sulfide, fluororesin, silicone, polyimide, polybenzimidazole, polyamide elastomer, those Together they look, and include their derivatives, and the like.

  Examples of suitable thermosetting resins include phenolic resin, urea resin, melamine-formaldehyde resin, urea-formaldehyde latex, xylene resin, diallyl phthalate resin, epoxy resin, aniline resin, furan resin, silicon resin, polyurethane resin, etc. Combinations thereof, derivatives thereof and the like.

B. Carbon nanomaterials Carbon nanomaterials are included in composite materials to impart desirable properties to the composite materials. The novel properties of composite materials are due, at least in part, to carbon nanostructures that form all or part of the carbon nanomaterial. Carbon nanostructures in carbon nanomaterials have beneficial properties such as unique shape, size, and / or electrical properties. In one embodiment, the carbon nanostructure is a carbon nanosphere.

  The carbon nanomaterial may include materials other than carbon nanospheres. For example, the carbon nanomaterial can include graphite (ie, a graphite sheet), amorphous carbon, and / or iron nanoparticles. The proportion of carbon nanospheres can affect the properties of the composite material. In one embodiment, the weight percentage of carbon nanospheres in the carbon nanomaterial ranges from about 2% to about 100% by weight. In one embodiment, the proportion of carbon nanospheres is at least about 10% by weight, more preferably at least about 15%.

  On the other hand, or in addition to the weight percent of carbon nanostructures, new carbon nanomaterials can be characterized by the lack of surface functional groups. In one embodiment, the functionality of the carbon nanomaterial is determined by the acidity of the wash liquor. In one embodiment, the carbon nanomaterial has a pH of the wash liquor in the range of about 5.0 to about 8.0, more preferably when the weight ratio of the wash liquor to the carbon nanomaterial is 1: 1. It has an acid functionality that provides a value in the range of about 6.0 to about 7.5, most preferably in the range of about 6.5 to about 7.25. The carbon nanomaterial having a pH in the above range can be advantageously mixed with a polymer resin (for example, polystyrene butadiene rubber) sensitive to an acidic filler material. However, the invention includes carbon nanomaterials having a pH outside the above range, and if required, these carbon nanomaterials can be used with polymers that are sensitive to acidic filler materials.

1. Carbon nanospheres Carbon nanospheres are hollow nanoparticles with a regular or irregular shape. In one embodiment, the carbon nanospheres are generally spheroid shaped.

  As described below, in one embodiment of the invention, carbon nanostructures are fabricated from template nanoparticles and a carbon precursor. During this process, carbon nanostructures are generated around the template nanoparticles. In this embodiment, the size and shape of the nanostructure is largely determined by the size and shape of the template nanoparticles. Since the carbon nanostructures are created around the template nanoparticles, the hole or inner diameter of the carbon nanostructure typically corresponds to the outer diameter of the template nanoparticles. The inner diameter of the carbon nanostructure may be between 0.5 nm and about 90 nm.

  1A and 1B are SEM images of examples of nanospheres made using catalyst-templated nanoparticles, the details of which are described in Example 1 below. 2 and 3 are TEM images of the nanomaterial shown in FIGS. 1A and 1B. The TEM image interpreted in view of the SEM image, in one embodiment, the nanospheres may generally have a spheroid shape.

  In FIG. 1A, the SEM image, in at least some embodiments, the carbon nanomaterial comprises spheroid or “grape” -like clusters of carbon nanospheres. FIG. 1B is a close-up of a cluster of carbon nanospheres that has been partially broken and opened inside, thereby revealing multiple carbon nanospheres. The TEM image of FIG. 2 further shows that the cluster is composed of multiple smaller nanospheres. The cluster of nanospheres in FIG. 2 reveals that the nanostructure is hollow and generally spheroid.

  FIG. 3 is a more detailed image of a carbon nanosphere that appears to have iron template nanoparticles in its center. The carbon nanospheres in FIG. 3 show that the formation of carbon nanostructures occurs around the catalyst template nanoparticles.

  In many carbon nanospheres observed in TEM images, the outer diameter of the nanosphere is between about 10 nm and about 60 nm, and the hollow center diameter is about 10 nm to about 40 nm. However, the present invention includes nanostructures having larger diameters and smaller diameters. Typically, carbon nanospheres have an outer diameter of less than about 100 nm to maintain structural consistency.

  The thickness of the nanosphere wall is measured from the inner diameter of the wall to the outer diameter of the wall. The thickness of the nanostructure can be varied during manufacture by limiting the degree of polymerization and carbonization of the carbon precursor as described below. Typically, the thickness of the carbon nanosphere wall is between about 1 nm and 20 nm. However, thicker and thinner walls can be made if necessary. The advantage of making a thick wall is greater structural consistency. The advantage of making thinner walls is greater surface area and porosity.

  Carbon nanostructure walls can also be formed from multiple graphite layers. In certain exemplary embodiments, the carbon nanospheres are between about 2 and about 100 graphite layers, more preferably between about 5 and about 50 graphite layers, and most preferably between about 5 and about 20 graphite layers. With walls. The graphite-like properties of carbon nanostructures are believed to give carbon nanostructures advantageous properties similar to those of multi-walled carbon nanotubes (eg, excellent conductivity). Carbon nanospheres are replaced with carbon nanotubes and can be used in many applications where carbon nanotubes can be used, but can often be used with good results and / or low cost as expected .

  Although SEM and TEM images generally show spherical nanostructures, the invention extends to nanostructures having shapes other than spheroids. In addition, the nanostructure may be a nanosphere fragment whose original shape has a spheroid shape. Typically, the shape of the carbon nanostructure will be determined at least in part by the shape of the template nanoparticles. Thus, the formation of non-spherical template nanoparticles can lead to carbon nanostructures having sizes that are not spheroids.

In addition to good electron transfer, the carbon nanostructures of the present invention may have high porosity and large surface area. Adsorption and desorption isotherms suggest that carbon nanostructures form mesoporous materials. The BET specific surface area of the carbon nanostructure is between about 80 and about 400 m ² / g, preferably greater than about 120 m ² / g, typically about 200 m ² / g, relative to the carbon nanotubes It is much larger than the typical value of 100 m ² / g that has been observed. Even in the case where the inventive method is carbon nanostructures combined with unstructured graphite, this graphite mixture (ie carbon nanomaterial) typically has a larger surface area than carbon nanotubes.

2. Methods for Producing Carbon Nanomaterials The carbon nanostructures of the present invention can be produced using all or part of the following steps: (i) carbon precursor and multiple template nanoparticles Forming a precursor mixture comprising: (ii) spontaneously polymerizing or causing polymerization of the carbon precursor around the catalyst-templated nanoparticles; (iii) carbonizing the precursor mixture to form a plurality of nanoparticles Forming an intermediate carbon material comprising a structure (eg, carbon nanosphere), amorphous carbon, and catalytic metal, (iv) removing at least a portion of the amorphous carbon and possibly a portion of the catalytic metal. (V) optionally purifying the intermediate carbon material by a heat treatment of the purified intermediate material. Removing at least some of the various functional groups remaining on the surface of the purified intermediate material by treatment of the purified and / or purified intermediate material with a base.

(I) Formation of Precursor Mixture The precursor mixture is formed by selecting a carbon precursor and dispersing a plurality of catalyst template nanoparticles in the carbon precursor.

  As the carbon precursor of the present invention, any type of carbon material may be used as long as it can disperse the template particles and carbonize around the template particles by heat treatment. Examples of suitable polymerizable carbon precursors include resorcinol-formaldehyde gel, resorcinol, phenolic resin, melamine-formaldehyde gel, polyfurfuryl alcohol, polyacrylonitrile, sucrose, petroleum pitch and the like. Other polymerizable benzenes, quinones, and similar compounds can also be used as carbon precursors, as is well known to those skilled in the art. In one exemplary embodiment, the carbon precursor is an organic compound that can be polymerized by a hydrothermal reaction. Suitable organic compounds of this type include citric acid, acrylic acid, benzoic acid, acrylic esters, butadiene, styrene, cinnamic acid and the like.

  The catalyst-templated nanoparticles dispersed in the carbon precursor are supplied in a number of different ways. The template nanoparticles may be formed in the carbon precursor (ie, in situ) or may be formed in a separate reaction mixture and then mixed with the carbon precursor. In some cases, particle formation occurs in part in a separate reaction, followed by particle formation as the template particles are mixed and / or heated in the carbon precursor (eg, the precursor polymerization step is initiated). Is completed. Template nanoparticles may also be formed using dispersants that control one or more aspects of particle formation, or template nanoparticles may be made from metal salts.

  In one embodiment, the template nanoparticles are formed from a metal salt in a carbon precursor. In this embodiment, the template nanoparticles are formed by selecting one or more catalytic metal salts that can be mixed with the carbon precursor. The metal salt is mixed with the carbon precursor and then spontaneously or artificially forms nanoparticles in situ.

  In another embodiment, the template particles are formed (in situ or elsewhere) using a dispersant to control particle formation. In this embodiment, one or more types of catalyst atoms and one or more types of dispersants are selected. The dispersant is selected to promote the formation of nanocatalyst particles having the desired stability, size, and / or uniformity. Dispersants within the scope of this invention include a variety of small organic molecules, macromolecules, and oligomers. Dispersants interact with catalyst atoms dissolved or dispersed in a suitable solvent or carrier by a variety of mechanisms including ionic, covalent, van der Waals interactions / bonds, lone pair bonds, or hydrogen bonds. Can be combined.

  It reacts or binds with a catalyst atom (eg, a ground state metal or metal salt form) and a dispersant (eg, a carboxylic acid or salt form) to form a complex catalyst. Complex catalysts are generally formed by first dissolving the catalyst atoms and the dispersant in a suitable solvent and then combining the catalyst atoms with the dispersant molecules. The various components can be combined or mixed in various orders or combinations. In addition, a subset of the components may be premixed before mixing with other components, or all components may be combined simultaneously.

  In one embodiment of the present invention, the components for the template nanoparticles are spontaneously or artificially formed into nanoparticles by mixing the components for a period of about 1 hour to about 14 days. Mixing typically takes place in the temperature range of 0 ° C to 200 ° C. In one embodiment, the temperature does not exceed 100 ° C. Particle formation can also be induced using reagents. For example, in some cases the formation of particles or intermediate particles can be caused by bubbling hydrogen through a solution of the complex catalyst.

  The template nanoparticles of the present invention can catalyze the polymerization and / or carbonization of a carbon precursor. The concentration of catalyst-templated nanoparticles in the carbon precursor is typically selected to maximize the number of carbon nanostructures that are formed. The amount of catalyst template particles varies depending on the type of carbon precursor used. In one example embodiment, the molar ratio of carbon precursor to catalyst atoms is from about 0.1: 1 to about 100: 1, more preferably from about 1: 1 to about 30: 1. Examples of suitable catalyst materials include iron, cobalt, nickel and the like.

(Ii) Polymerization of the precursor mixture The precursor mixture is typically cured for a sufficient amount of time such that a plurality of intermediate carbon nanostructures are formed around the template nanoparticles. Because the template nanoparticles have catalytic activity, the template nanoparticles can preferentially accelerate and / or initiate polymerization of the carbon precursor near the template particle surface.

  The time required to form the intermediate nanostructure depends on the temperature, the type and concentration of the catalyst material, the pH of the solution, and the type of carbon precursor used. During polymerization, the intermediate carbon nanostructures may be individual organic structures or nanostructure aggregates that break apart and leave upon carbonization and / or removal of amorphous carbon.

  Ammonia added to adjust the pH can also affect the polymerization by increasing the polymerization rate and by increasing the amount of crosslinking that occurs between the precursor molecules.

  For carbon precursors that can be polymerized by hydrothermal reaction, the polymerization typically occurs at elevated temperatures. In a preferred embodiment, the carbon precursor is heated to a temperature between about 0 ° C. and about 200 ° C., more preferably between about 25 ° C. and about 120 ° C.

  Examples of suitable conditions for the polymerization of resorcinol-formaldehyde gels (eg, solutions containing iron particles and pH 1-14) include solution temperatures between 0 ° C. and 90 ° C. and cure times of less than 1 hour to about 72 hours. It is. One skilled in the art can readily determine the conditions necessary to cure other carbon precursors under the same or different parameters.

  In one embodiment, the polymerization reaction does not continue until complete. Stopping the curing process before the entire solution is polymerized may facilitate the formation of multiple intermediate nanostructures that result in individual nanostructures rather than a single mass of carbonized material. However, the present invention includes embodiments in which the carbon precursors form a plurality of intermediate carbon nanostructures that are connected or partially connected to each other. In this embodiment, individual nanostructures are formed upon carbonization and / or upon removal of amorphous carbon.

  Forming intermediate carbon nanostructures from a dispersion of template nanoparticles facilitates the formation of multiple intermediate carbon nanostructures having unique shapes and sizes. Ultimately, the nature of the nanostructure depends at least in part on the shape and size of the intermediate carbon nanostructure. Because of the unique shape and size of the intermediate carbon nanostructure, the final nanostructure can have advantageous properties such as high specific surface area and high porosity, among others.

(Iii) Carbonization of precursor mixture The precursor mixture is carbonized by heating to form an intermediate carbon material comprising a plurality of carbon nanostructures, amorphous carbon, and catalytic metal. The precursor mixture can be carbonized by heating the mixture at a temperature between about 500 ° C and about 2500 ° C. During the heating process, atoms such as oxygen and nitrogen are removed from the intermediate nanostructures (or carbon around the template nanoparticles) by transpiration or other mechanism, and the carbon atoms rearrange or coalesce to form a carbon-based structure. Form.

The carbonization step typically creates a graphite-based nanostructure. Graphite-based nanostructures have carbon atoms arranged in a structural sheet of sp ² hybridized carbon atoms. Graphite layers can provide unique and useful properties such as electrical conductivity and structural strength and / or stiffness.

(Iv) Purification of intermediate carbon material The intermediate carbon material is purified by removing at least a portion of the amorphous carbon having no graphite structure. This purification step increases the weight percent of carbon nanomaterials in the intermediate carbon material.

Amorphous carbon is typically removed by oxidation of the carbon. The oxidant used to remove amorphous carbon works selectively against the oxidation of bonds found in amorphous carbon that does not have a graphite structure, but against the π bonds of graphite-like carbon nanostructures. Is less reactive. Amorphous carbon is removed by the action of an oxidant or oxidant mixture in one or more successive purification steps. The reagent for removing amorphous carbon includes an acid having an oxidizing action, an oxidizing agent, and a mixture thereof. Examples of mixtures suitable for removal of amorphous carbon include sulfuric acid, KMNO ₄ , H ₂ O ₂ , 5M or even higher concentrations of HNO ₃ and aqua regia.

  In some cases, virtually all or part of the catalytic metal may be removed. Whether the catalytic metal is removed and to what extent the catalytic metal is removed depends on the application for which the carbon nanomaterial is needed. In some embodiments of the invention, the presence of a metal such as iron may be advantageous to impart certain electrical and / or magnetic properties. On the other hand, it may be desirable to remove the catalyst metal to prevent the catalyst metal from having the opposite effect on the final application. Removal of catalyst template particles also improves porosity and / or reduces density.

  Typically, template nanoparticles are removed using an acid or base such as nitric acid, hydrogen fluoride, or sodium hydroxide. The method of removing template nanoparticles or amorphous carbon depends on the type of template nanoparticles or catalyst atoms in the composite material. Catalyst atoms or particles (eg, iron particles or atoms) are typically removed by refluxing the composite nanostructure in a 5.0 M nitric acid solution for about 3-6 hours.

  Any removal process may be used to remove template nanoparticles and / or amorphous carbon as long as the removal process does not completely destroy the carbon nanostructure. In some cases, it may even be advantageous to remove at least partially some carbonaceous material from the intermediate nanostructure during the purification process.

  During the purification process, oxidants and acids are present on the surface of the carbonaceous material, but are not limited to hydronium and oxidative groups such as carboxylic acid ester, carbonyl, and / or ether groups. There is a tendency to introduce. It is believed that functional groups may be present on the surface of carbon nanostructures, graphite mixed with carbon nanostructures, and / or amorphous carbon that does not have residual graphite structures.

(V) Removal of functional groups from the surface of the intermediate carbon material In some cases, the functional groups on the surface of the intermediate carbon material may be removed using a heat treatment step and / or a base for neutralization. it can. The removal of surface functional groups and / or neutralization of surface functional groups typically improves the dispersion of carbon nanomaterials in the polymeric material and / or the composite material removal or neutralization. This is done to improve the properties.

  Functional groups on the surface of the intermediate carbon material can be removed using a heat treatment step. The heat treatment step is advantageously performed at a temperature selected depending on the particular functional group that needs to be removed. In general, the higher the heat treatment temperature, the more types of functional groups that can be removed. The heat treatment step following purification can be performed at a temperature above about 100 ° C, more preferably at a temperature above about 200 ° C, and most preferably at a temperature above about 500 ° C.

  In some cases, the heat treatment following purification can be performed at a temperature sufficient to carbonize the amorphous carbon. Surprisingly, heating the intermediate carbon material to carbonization temperature after purification can conveniently convert a significant portion of any remaining amorphous carbon to graphite. It has been found that the remaining carbon can be more easily converted to graphite by removing a significant proportion of the amorphous carbon in the purification step and carbonizing the purified material.

  Graphite formed in this second carbonization step can be added to carbon nanostructures or secondary carbon nanostructures (eg nanosphere grape-like aggregates) or mixed with carbon nanostructures. Free graphite. Converting the remaining amorphous carbon to graphite significantly increases the graphite purity of the carbon nanostructure. High purity carbon nanomaterials can be made more efficiently by using the two-step carbonization method of the present invention compared to attempts to achieve the same level of purity in a single carbonization step.

In another embodiment, or in addition to an additional heat treatment step, some functional groups such as, but not limited to, hydronium ions may provide a base to neutralize from the intermediate carbon material. Use to be removed. In this embodiment, the intermediate carbon material is mixed with a solution containing one or more neutralizing bases. Suitable bases include hydroxides including sodium hydroxide and potassium hydroxide, ammonia, lithium acetate, sodium acetate, potassium acetate, NaHCO ₃ , KHCO ₃ , Na ₂ CO ₃ , K ₂ CO ₃ , and the like A combination is included. The reaction between the base and the hydronium group can produce a by-product that can be removed by washing with water.

  In one embodiment, the functional groups are removed by immersing the intermediate carbon material in a cleaning solution. Additional base can be added to the wash solution until the pH reaches the desired, more neutral pH. In one embodiment, the wash solution is neutralized to a pH range of about 5.0 to about 8.0, or alternatively to a pH range of about 6.0 to about 7.5.

  The process of removing functional groups from carbon nanomaterials can include removing functional groups in other components of either carbon nanostructures, amorphous carbon (graphite or non-graphite), or purified intermediate carbon materials. Can be used for In one embodiment, the functional groups are removed from the carbon nanostructure or other graphite material that forms part of the carbon nanomaterial. The high temperature heat treatment step can also be advantageous if it is desired to remove certain impurities, such as iron, in addition to removing functional groups from the nanomaterial.

  Nanospheres can also be manufactured using other suitable techniques. The nanomaterial production method that can be appropriately used in the present invention is disclosed in Patent Document 2 and Patent Document 3, both of which have been filed by the present applicant, together with Non-Patent Document 1, the entire contents of which are incorporated herein by reference. Cited and incorporated.

C. Additives Additives such as fillers or dispersants can be added to the polymeric material to impart desired properties to the composite material and / or to disperse the carbon nanospheres in the polymer. Any filler material may be used in the present invention. Suitable fillers include carbon black, silica, diatomaceous earth, ground quartz, talc, clay, mica, calcium silicate, magnesium silicate, glass powder, calcium carbonate, barium sulfate, zinc carbonate, titanium oxide, alumina, glass Fibers, other carbon fibers, and organic fibers are included. Other suitable additives include softeners, plasticizers, molding aids, lubricants, anti-aging agents, and UV absorbers.

II. Method of making a composite material incorporating carbon nanospheres The composite material of the present invention comprises an amount of carbon nanospheres as a polymeric material, and optionally one or more additives such as fillers and dispersants. Formed by mixing with. The carbon nanospheres are in the range of about 0.1% to about 70% by weight of the composite material, more preferably in the range of about 0.5% to about 50%, most preferably about 1.0%. To about 30% by weight can be mixed with the polymeric material.

  Carbon nanospheres can be added to the polymeric material in a substantially pure form. On the other hand, carbon nanospheres can also be added to polymer materials as a component of carbon nanomaterials. In one embodiment, the carbon nanospheres are at least about 2%, more preferably at least about 10%, and most preferably at least about 15% by weight of the carbon nanomaterial.

  When mixed with the polymeric material of the present invention, carbon nanospheres offer unique advantages due to the spheroid shape of the nanospheres. In contrast to carbon nanotubes, which are fibrous, carbon nanospheres have a more particle-like shape. In some embodiments of the invention, the particulate shape imparts properties to the composite material much like a particulate filler rather than a fiber-containing composite material.

Carbon nanospheres can be added in an amount that gives the polymer material the desired properties. For example, carbon nanospheres can be added in an amount that imparts electrical conductivity to the polymeric material and / or reduces surface resistance. Surprisingly, the amount of carbon nanospheres required to achieve the desired reduction in surface electrical resistance is significantly greater than the amount of carbon nanotubes or carbon black required to achieve the same reduction in resistance. Few. It is believed that the carbon nanomaterials exhibit the improvement due to the more uniform particle network that allows improved percolation compared to carbon nanotubes. Low surface resistance is particularly noticeable on the polished surface. In one embodiment, the polymer composite of the present invention has a loading in the range of about 0.5% to about 7%, more preferably about 1% to about 5% by weight of the carbon nanosphere, The surface resistance is in the range of about 1 × 10 ⁴ to about 1 × 10 ⁶ (Ω / sq).

  In addition to electrical conductivity, carbon nanospheres can be introduced into polymer materials as flame retardants.

  As a method for producing the composite material of the present invention, any known method can be used. In one embodiment of the invention, the composite material is made by melting the polymeric material and then mixing the polymer and the carbon nanomaterial. On the other hand, a polymer material can be prepared (that is, polymerized) in the presence of carbon nanospheres.

  For example, a pellet or powder of polymeric material and a desired amount of carbon nanospheres can be dry blended or wet blended and then mixed with a roll kneader while heated. On the other hand, the mixed composite material can also be fed to an extruder to extrude the composite material as a rope and then cut into pellets.

  On the other hand, carbon nanospheres can also be blended in a liquid medium as a solution or resin dispersion. The composite material can also be mixed by a wet masterbatch method. If a thermosetting resin is used, the carbon nanospheres can be mixed with the monomer or oligomer in any known manner appropriate to the individual polymerizable material.

  Any known method and material suitable for use with graphitic carbon can be used to improve the dispersibility of the nanospheres in the polymeric material. Furthermore, any known method such as extrusion molding, blow molding, injection molding, or press molding can be used as a method of molding into a desired shape.

  The composite material of the present invention can be made into a foamed product by adding a foaming agent in order to obtain a foamed resin having electrical conductivity and / or blackness. Any of the various polymeric materials mentioned above will create a foamed product similar to thermoplastics such as polyethylene, polypropylene, polyvinyl chloride, polystyrene, polybutadiene, polyurethane, ethylene-vinyl acetate copolymer, etc. A thermoplastic polymer material is preferred. As the foaming agent, various resin foaming agents and organic solvents can be used as well as gas such as butane.

  Any known method may be used as a method for producing an electrically conductive foam within the scope of the present invention. For example, if a thermoplastic resin is used, the resin is melted and mixed with the desired amount of carbon nanospheres by an extruder. A gas such as butane is then injected into the polymeric material. As an alternative, chemical blowing agents can be used instead of gas.

  Formulations within the scope of the present invention are also useful as paints for imparting electrical conductivity and / or blackness to other substrate surfaces. Suitable substrates include various resins, elastomers, rubber, wood, inorganic materials, and the like. In addition, these materials can be further molded or foamed.

  The desired thickness of coatings of such formulations that fall within the scope of the present invention is greater than 0.1 microns.

III. Examples The following examples provide formulations for making carbon nanomaterials comprising carbon nanostructures according to one embodiment of the present invention.

Example 1
Example 1 describes a method for preparing a carbon nanomaterial containing carbon nanospheres.

(A) Preparation of iron solution (0.1 M) A 0.1 M iron solution is prepared using 84 g iron powder, 289 g citric acid, and 15 L water. The iron-containing mixture is mixed on a stirring table in a closed bottle for 3 days with one or two short breaks per day to purge the vapor space of the bottle with air before resuming mixing Is done.

(B) Preparation of precursor mixture 916.6 g of resorcinol and 1350 g of formaldehyde (37% aqueous solution) are placed in a round bottom flask. Stir the solution until the resorcinol is completely dissolved. When the 15 L iron solution prepared in step (a) is slowly added with stirring and then 1025 ml ammonium hydroxide (28-30% aqueous solution) is added dropwise with vigorous stirring, the pH of the resulting suspension is 10 .26. The slurry is cured at 80-90 ° C. (water bath) for 10 hours. The solid carbon precursor mixture is then collected by filtration and dried in an oven overnight.

(C) Carbonization The polymerized precursor mixture is placed in a covered crucible and transferred to a heating furnace. The carbonization process is performed under a sufficient nitrogen stream using the following temperature program: room temperature → 1160 ° C. → 1160 ° C. for 5 hours at a rate of 20 ° C./min→room temperature. The carbonization step provides an intermediate carbon material that includes carbon nanostructures, amorphous carbon, and iron.

(D) Purification to remove amorphous carbon and iron Purification of the carbonized carbon product (ie, intermediate carbon material) is performed as follows: reflux the carbonized product in 5M HNO ₃ for about 12 hours. → washing with deionized (DI) -H ₂ 0 → treatment with a mixture of KMnO ₄ + H ₂ SO ₄ + H ₂ O at a molar ratio of 1: 0.01: 0.003 (kept at about 90 ° C. for about 12 hours) → DI Wash with H ₂ O → treat with 4M HCl (kept at about 90 ° C. for about 12 hours) → wash with DI-H ₂ 0 → collect the product and dry in oven at about 100 ° C. for 2 days.

(E) Heat treatment to reduce surface functional groups After the purification process, the carbon product undergoes heat treatment to minimize surface functional groups and increase the graphite content. The temperature program used for this treatment is as follows: heating from room temperature at 4 ° C./min→100° C. → holding at 100 ° C. for 2 hours → 250 ° C. at 15 ° C./min→2 hours at 250 ° C. Holding → 1000 ° C. at 15 ° C./min→holding at 1000 ° C. for 2 hours → room temperature. By this heat treatment process, a carbon nanomaterial mainly composed of carbon nanospheres is obtained.

  Next, the carbon nanomaterial produced in Example 1 was analyzed by SEM and TEM. SEM images of carbon nanostructures are shown in FIGS. 1A and 1B, revealing that a plurality of carbon nanospheres aggregate to form a cluster with a vine shape. The TEM images in FIGS. 2 and 3 show that this grape-like cluster is composed of multiple small, hollow, graphite-like nanostructures or carbon nanospheres.

  The graphite content of the carbon nanostructure of Example 1 was examined using X-ray diffraction. FIG. 4 is a graph showing an X-ray diffraction pattern of the carbon nanomaterial of Example 1. The broad peak at about 26 ° is due to the short range order of the graphitic nanostructure. This is in contrast to the diffraction pattern of typical graphite sheets that tend to have very narrow peaks. Since amorphous carbon tends to have a diffraction peak at 20 °, a broad peak at about 26 ° also suggests that the material is graphite-like.

Raman spectroscopy was used to determine the graphite content of the carbon nanomaterial at various temperatures during the heat treatment process (e). Sample A was taken from the carbon nanomaterial at a heat treatment temperature of 1000 ° C., Sample B was taken during the heat treatment to 600 ° C., and Sample C was a sample that had not been heat treated (ie, Sample C is the purified intermediate carbon material of step (d)). The result of Raman spectroscopy is shown in FIG. The graph of FIG. 5 has two important peaks, one at 1354 cm ⁻¹ and the other at 1581 cm ⁻¹ . As shown in this graph, heat-treated samples A and B show a larger peak at 1354 cm ⁻¹ . These peaks suggest that the amorphous carbon is graphite-like and therefore not burned out (ie, less weight loss). In contrast, the 1354 cm ⁻¹ peak for Sample C shows a significant weight loss, suggesting amorphous carbon that is not graphitic. Thus, in addition to functional group removal, the heat treatment step is effective in increasing the graphite content for any residual carbon. Surprisingly, this conversion can occur at relatively low temperatures, for example between 500 ° C and 1400 ° C.

  The higher graphite content of carbon nanomaterials produced using an additional heat treatment step according to the present invention results in carbon nanomaterials having excellent conductivity and purity. In addition to improving the graphite concentration, the heat treatment significantly reduces other impurities such as iron.

Example 2
Example 2 describes a carbon nanomaterial produced by the same method as Example 1 except that in step (e) the heat treatment step is replaced with a base treatment for neutralization.

A portion of the purified carbon material obtained in step (d) of Example 1 is mixed with a sufficient amount of DI-H ₂ O, then 5M NaOH is added dropwise to bring the pH of the solution to about 7.0. Kept. The resulting carbon nanomaterial was collected by filtration and washed with a sufficient amount of DI-H ₂ O to remove Na ⁺ ions. The final product was collected and dried in an oven at about 100 ° C. for 2 days.

Example 3: Comparative Example For comparison purposes, a portion of the purified carbon material obtained in step (d) of Example 1 was collected and a heat treatment step described in Step (e) of Example 1 was also performed. The base treatment for neutralization in Example 2 was also omitted.

  TEM images of the carbon nanostructures of Examples 2 and 3 were obtained to determine if any structural change occurred during the neutralization step. Compared to FIG. 6 which is the TEM of the carbon material of Example 3 (ie before neutralization), FIG. 7 which is the TEM of the carbon material of Example 2 (ie after neutralization) shows any harmful effects on the carbon nanostructure. It shows that there is no significant influence.

  The advantageous nature of the acid-free carbon nanomaterial of Example 2 is that it includes a nanomaterial that is the same except that the acid-free nanomaterial is introduced into the polymer and it has the presence of acidic functional groups. It can be explained by comparing with molecules. To test this scenario, the carbon nanomaterials of Examples 2 and 3 were separately mixed with the polymer. FIG. 8 shows a polymer comprising a carbon nanomaterial having acidic functional groups. This polymer exhibits considerable blistering and irregularities on its surface. In contrast, the polymer comprising the neutralized carbon nanomaterial of Example 2 exhibits a smooth surface.

  The present invention may be implemented in other specific forms without departing from the spirit and essential characteristics thereof. The described embodiments are to be considered in all respects as illustrative and not restrictive. Accordingly, the scope of the invention is indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

1 is a high resolution SEM image of a carbon nanomaterial formed according to one embodiment of the present invention, including a plurality of nanosphere clusters. FIG. It is a more detailed high-resolution SEM image showing individual clusters of carbon nanostructures, and is a diagram in which a plurality of carbon nanostructures constitutes a cluster from one cluster that reveals a broken interior. . 1B is a high-resolution TEM image of the carbon nanostructure of FIG. 1A, revealing multiple wall and hollow properties of the carbon nanostructure in which multiple carbon nanostructures aggregate together to form a cluster. FIG. 3 is a high-resolution TEM image showing a close-up of a carbon nanostructure having a catalyst-templated nanoparticle at its center. It is a figure which shows the X-ray-diffraction intensity of the carbon nanostructure of FIG. 1A. FIG. 4 is a graph showing a Raman spectrum of carbon nanomaterials manufactured according to the present invention, showing that different carbon nanomaterials are produced as a result of different heat treatments. FIG. 2 is a high resolution TEM of a purified intermediate carbon material that has been produced according to the present invention but has not been treated to remove functional groups. FIG. 7 shows a high resolution TEM of the carbon nanomaterial of FIG. 6 that has been treated with a base to remove functional groups. It is a figure which shows the image of the polymer which contains the refined intermediate carbon material of FIG. 6 in it. It is a figure which shows the image of the polymer which introduce | transduced the carbon nanomaterial of FIG.

Claims (26)

A composite material,
A polymeric material including a polymer or a polymerizable material; and
A composite material comprising: a plurality of carbon nanospheres dispersed in the polymeric material, wherein the plurality of carbon nanospheres comprises at least about 0.1% by weight of the composite material.   The composite of claim 1, wherein the carbon nanospheres comprise hollow multi-wall particles having an outer diameter of less than about 1 micron.   The composite material of claim 1, wherein the carbon nanospheres comprise at least about 0.5% by weight of the composite material.   The composite material of claim 1, wherein the carbon nanospheres comprise at least about 1% by weight of the composite material.   Carbon nanomaterials other than carbon nanospheres, and carbon nanospheres, wherein the carbon nanospheres comprise at least about 2% by weight of the total weight of the carbon nanomaterials in the composite material The composite material according to claim 1, further comprising an added carbon nanomaterial.   6. The composite material of claim 5, wherein the carbon nanosphere comprises at least about 3% by weight of the total weight of the carbon nanomaterial in the composite material.   6. The composite material of claim 5, wherein the carbon nanosphere comprises at least about 15% by weight of the total weight of the carbon nanomaterial in the composite material.   The polymer material is polyamine, polyacrylate, polybutadiene, polybutylene, polyethylene, chlorinated polyethylene, ethylene vinyl alcohol, fluorine polymer, ionomer, polymethylpentene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, Condensed polymer, polyamide, polyamideimide, polyaryletherketone, polycarbonate, polyketone, polyetheretherketone, polyetherimide, polyethersulfone, polyimide, polyphenyleneoxide, polyphenylenesulfide, polyphthalamide, polyphthalimide, polysulfone, Polyarylsulfone, allyl resin, melamine resin, phenol formaldehyde resin, liquid crystal polymer, polyolefin, polyester , Silicone, polyurethane, epoxy, cellulosic polymers, and composite material according to claim 1, characterized in that it comprises a polymer selected from the group consisting of.   The polymer materials are acrylonitrile-butadiene-styrene, acrylonitrile-ethylene / propylene-styrene, methyl methacrylate-butadiene-styrene, acrylonitrile-butadiene-methyl methacrylate-styrene, acrylonitrile-n-butyl acrylate-styrene, rubber modified. Polystyrene, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polyvinyl chloride, cellulose acetate resin, polyamide, polyester, polyacrylonitrile, polycarbonate, polyphenylene oxide, polyketone, polysulfone, polyphenylene sulfide, fluororesin, silicone, polyimide, polybenz Thermoplastic selected from the group consisting of imidazole, polyamide elastomer, and combinations thereof The composite material according to claim 1, characterized in that it comprises a polymeric material.   The polymer material is selected from the group consisting of phenolic resin, urea resin, melamine-formaldehyde resin, urea-formaldehyde latex, xylene resin, diallyl phthalate resin, epoxy resin, aniline resin, furan resin, polyurethane, and combinations thereof. The composite material according to claim 1, further comprising a thermosetting polymer material. A composite material comprising a polymer or polymerizable material and a carbon nanomaterial mixed therewith, wherein the composite material comprises:
Forming a precursor mixture comprising a plurality of template nanoparticles comprising a carbon precursor and a catalytic metal;
Carbonizing the precursor mixture to form an intermediate carbon material comprising a plurality of carbon nanostructures, amorphous carbon, and optionally remaining catalytic metal;
Purifying the intermediate carbon material by removing at least a portion of the amorphous carbon and possibly a portion of the remaining catalytic metal to obtain a carbon nanomaterial;
The carbon nanomaterial is mixed with a thermoplastic or polymerizable material in liquid or plasticizing condition and solidified such that the thermoplastic polymer or polymerizable material produces the composite material. Or a composite material characterized in that it is produced by a method comprising the steps of leading to solidification. The method for producing the carbon nanomaterial comprises:
(I) heating the purified intermediate carbon material to a temperature greater than about 100 ° C. and / or
(Ii) treating the purified intermediate carbon material with a base;
The composite material according to claim 11, further comprising removing functional groups from a surface of the purified intermediate carbon material.   12. The composite material of claim 11, wherein the method of manufacturing the carbon nanomaterial comprises heating the purified intermediate carbon material to a temperature greater than about 200 degrees Celsius.   12. The composite material of claim 11, wherein the method of manufacturing the carbon nanomaterial comprises heating the purified intermediate carbon material to a temperature greater than about 500 degrees Celsius.   12. The composite material of claim 11, wherein the method of manufacturing the carbon nanomaterial comprises heating the purified intermediate carbon material to a temperature greater than about 1000 degrees Celsius.   12. A composite material according to claim 11, wherein the method of producing the carbon nanomaterial comprises treating the purified intermediate carbon material with sodium hydroxide and / or potassium hydroxide.   The composite materials are acrylonitrile-butadiene-styrene, acrylonitrile-ethylene / propylene-styrene, methyl methacrylate-butadiene-styrene, acrylonitrile-butadiene-methyl methacrylate-styrene, acrylonitrile-n-butyl acrylate-styrene, rubber modified Polystyrene, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polyvinyl chloride, cellulose acetate resin, polyamide, polyester, polyacrylonitrile, polycarbonate, polyphenylene oxide, polyketone, polysulfone, polyphenylene sulfide, fluororesin, silicone, polyimide, polybenzimidazole A polymer selected from the group consisting of polyamide elastomers, and combinations thereof Composite material according to claim 11, wherein Mukoto. A method of making a composite material, comprising:
Providing a thermoplastic polymer or polymerizable material in liquid or plasticizing conditions;
Mixing a graphite-like material comprising 3% by weight or more of carbon nanospheres into the thermoplastic polymer or polymerizable material between about 1% and 50% by weight;
Solidifying the thermoplastic polymer or polymerizable material to produce the composite material or leading to solidification. A method of making a composite material.   In the method in which the composite material is formed from a thermoplastic polymer, the thermoplastic polymer is placed in a liquid or plasticizing condition before or during mixing with the graphite-like substance. 19. The method of claim 18, comprising heating to a temperature higher than a melting point or glass transition temperature of the thermoplastic polymer, and then cooling the thermoplastic polymer to produce the composite material. The method described.   The thermoplastic polymer is acrylonitrile-butadiene-styrene, acrylonitrile-ethylene / propylene-styrene, methyl methacrylate-butadiene-styrene, acrylonitrile-butadiene-methyl methacrylate-styrene, acrylonitrile-n-butyl acrylate-styrene, rubber. Modified polystyrene, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polyvinyl chloride, cellulose acetate resin, polyamide, polyester, polyacrylonitrile, polycarbonate, polyphenylene oxide, polyketone, polysulfone, polyphenylene sulfide, fluororesin, silicone, polyimide, poly Selected from the group consisting of benzimidazole, polyamide elastomer, and combinations thereof. The method of claim 19, wherein.   19. The method of claim 18, wherein the composite material is formed from a polymerizable material that is initially in liquid or plasticizing conditions and subsequently polymerizes to form a polymeric material.   The polymerizable material is polyacrylic acid ester, polybutadiene, polybutylene, polyethylene, chlorinated polyethylene, ethylene vinyl alcohol, fluoropolymer, ionomer, polymethylpentene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, condensation Polymer, polyamide, polyamideimide, polyaryletherketone, polycarbonate, polyketone, polyetheretherketone, polyetherimide, polyethersulfone, polyimide, polyphenyleneoxide, polyphenylenesulfide, polyphthalamide, polyphthalimide, polysulfone, polysulfone Aryl sulfone, allyl resin, melamine resin, formaldehyde resin, liquid crystal polymer, polyolefin, polyester, silicone, polyester Urethane, epoxy, cellulosic polymers, and methods of claim 21, which comprises a suitable monomer or oligomer to form a polymeric material selected from the group consisting of. The carbon nanosphere is the next step,
(I) forming one or more intermediate carbon nanospheres by polymerizing a carbon precursor in the presence of a plurality of template nanoparticles;
(Ii) carbonizing said intermediate carbon nanosphere to form a plurality of composite nanostructures;
19. The method of claim 18, wherein (iii) is optionally produced according to the step of removing the template nanoparticles from the composite nanostructure to obtain the carbon nanospheres.   24. The method of claim 23, wherein the template nanoparticles comprise at least one of iron, nickel, or cobalt.   24. The method of claim 23, wherein the carbonization is performed at a temperature between about 500 degrees Celsius and about 2500 degrees Celsius.   24. The method of claim 23, wherein the template nanoparticles are removed from the composite nanostructure by etching with acid, base, or both.

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