KR101415255B1 - Post-treatment method of carbon nanotube fibers to enhance mechanical property - Google Patents

Abstract

More particularly, the present invention relates to a process for post-treatment of carbon nanotube fibers, and more particularly, to a process for post-treatment of carbon nanotube fibers, To a carbon nanotube fiber post-treatment method capable of obtaining carbon nanotube fibers having improved mechanical properties by reacting them with nanotubes.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a carbon nanotube fiber post-

More particularly, the present invention relates to a method of post-treatment of carbon nanotube fibers for improving mechanical strength, and more particularly, to a method of post-treatment of carbon nanotube fibers, The present invention relates to a carbon nanotube fiber post-treatment method for enhancing mechanical strength, which enables to obtain carbon nanotube fibers having improved mechanical properties by reacting with carbon nanotubes constituting fibers.

Carbon nanotubes, which are formed by hexagonal ring-shaped carbons in a round shape with a diameter of nanometer size, have a tensile strength 100 times stronger than steel, a current density 1000 times higher than copper, and a very excellent characteristic .

Such carbon nanotubes have various mechanical and electrical properties depending on the arrangement of the hexagonal rings constituting the carbon nanotubes and the number of walls, and the physical properties of the individual carbon nanotubes are not limited to those of commercialized high-functional fibers such as carbon fibers, kevlar, And is applied to transparent electrodes, composite materials and the like.

The fibrous carbon nanotube aggregate, that is, the carbon nanotube fibers existing in a continuous phase rather than the particle type like the individual carbon nanotubes, has no problems such as the difficulty of dispersion of the carbon nanotubes in the form of particles, Or a two-dimensional fabric, and can be utilized in various ways. Also, the density is 9 times smaller than that of carbon fiber, which is very effective for making light and strong materials like lightweight composite materials.

However, despite these merits, the carbon nanotube fiber has a disadvantage that it can not express the physical properties of the individual carbon nanotubes constituting it.

From the viewpoint of mechanical properties, the carbon nanotube fibers are present in a continuous fibrous form of individual carbon nanotubes, but when the fibers are subjected to a tensile force, the carbon nanotubes are easily broken without effectively dispersing the load. This is because the surface of the carbon nanotubes is smooth and chemically inert and weak van der Waals forces act between the individual carbon nanotubes.

In order to solve these problems, it is necessary to study a method of producing a high-quality fiber by changing the conditions for manufacturing the carbon nanotube fiber, that is, the spinning method, the kind and content of the carbon supply material and the synthesis temperature of the carbon nanotube, Researches are under way to improve the mechanical, electrical and thermal properties through post-treatment.

Among the methods of enhancing physical properties through post-treatment of fibers, fibers are physically twisted or immersed in a volatile solvent, followed by densification of the fiber structure through evaporation of the solvent to increase the strength and conductivity by increasing the contact area between carbon nanotubes There is a way to do it.

In addition, carbon nanotube fibers are impregnated into a polymer solution to form a fibrous composite material, or chemical cations or ultraviolet rays are used to form a strong covalent bond that complements the inherent weak van der Waals force between carbon nanotubes, thereby improving physical properties There is also a way to do it. However, since the above post-treatment methods are based on strength improvement by a physical method, there is a limit to obtaining high strength fibers.

Therefore, the inventors of the present invention have found that, in order to improve the physical properties of the carbon nanotube fibers, the strength of the fibers can be increased more effectively than the physical methods when the chemical bonding between the carbon nanotubes is induced, When an aromatic compound substituted with two amine groups or an aromatic compound in which one amine group and one halogen element are substituted is reacted with the carbon nanotube fibers and then heat treatment is performed, It is possible to obtain carbon nanotube fibers having improved mechanical properties in a short period of time under conditions, and to shorten the process time and increase the strength of the fibers.

U.S. Published Patent Application No. 2010/0112276 U.S. Published Patent Application No. 2009/0282802

J. Phys. Chem. C, Mark D. Ellison, 2008, 112, 738 Carbon, Jackie Y. Cai, 2012, 50, 4655 ACS Nano, Kai Liu, 2012, 4, 5827

In the present invention, carbon nanotube fibers that improve the mechanical properties of the carbon nanotube fibers by reacting the aromatic compounds substituted with two amine groups or aromatic compounds substituted with one amine group and one halogen element And it is an object of the present invention to provide a post-processing method.

According to an aspect of the present invention, there is provided a method of preparing carbon nanotube fibers, the method comprising: preparing carbon nanotube fibers comprising carbon nanotubes; An aromatic compound addition step of adding aromatic compounds substituted with a plurality of functional groups to the prepared carbon nanotube fibers; And forming a chemical bond between the aromatic compound and the one or more carbon nanotubes by reacting a plurality of functional groups of the added aromatic compound with one or more carbon nanotubes constituting the carbon nanotube fibers, ; The present invention provides a method for post-treatment of carbon nanotube fibers for improving mechanical strength.

In an exemplary embodiment, the plurality of functional groups is at least one functional group selected from the group consisting of an amine group, a halogen, an alkyne, a boric acid, and an azide .

In an exemplary embodiment, the plurality of functional groups are all amine groups, and in the bond formation step, the plurality of amine groups are reacted with the at least one carbon nanotube under temperature conditions of 50 to 100 ° C, It is preferable to form a chemical bond between the aromatic compound and the at least one carbon nanotube.

In an exemplary embodiment, the plurality of functional groups is an amine group and a halogen, and in the bond formation step, the amine group reacts with one carbon nanotube under temperature conditions of 50 to 70 ° C to form the aromatic compound Wherein the halogen is reacted with another carbon nanotube under a temperature condition of 150 to 250 ° C to form a chemical bond between the aromatic compound and the other carbon nanotube .

In an exemplary embodiment, the plurality of functional groups are all halogen, and the halogen is reacted with one or more carbon nanotubes under palladium or copper catalyst conditions to form a reaction between the aromatic compound and the one or more carbon nanotubes And the one or more carbon nanotubes each include an aromatic compound having an alkane group on the surface thereof, and the alkane reacts with the halogen to form a chemical bond between the aromatic compound.

In an exemplary embodiment, the plurality of functional groups are all boric acid, and in the bond formation step, the boric acid reacts with one or more carbon nanotubes under palladium catalyst conditions to form the aromatic compound and the one or more carbon nano- And the one or more carbon nanotubes each include an aromatic compound having a halogen group on its surface, and the halogen and the boric acid react with each other to form a chemical bond between the aromatic compounds.

In an exemplary embodiment, the plurality of functional groups are all alkyne, and in the bond formation step, the alkane reacts with one or more carbon nanotubes under Cu (I) catalyst conditions to react with the aromatic compound Wherein the one or more carbon nanotubes each include an aromatic compound having an azide group on the surface thereof so that the azide reacts with the alkane to form a chemical bond between the aromatic compound .

In an exemplary embodiment, the aromatic compound is preferably benzene.

Also, the present invention provides a carbon nanotube fiber post-treated by the above method.

The carbon nanotube fiber produced according to the carbon nanotube fiber post treatment method of the present invention has an effect of remarkably improving the mechanical properties, particularly the mechanical strength.

According to the carbon nanotube fiber post-treatment method of the present invention, it is possible to obtain carbon nanotube fibers improved in mechanical properties in a short time at a low temperature condition without injecting a separate adhesive material, And high strength of the fiber can be achieved, so that there is an effect of securing price competitiveness.

1 shows a brief mechanism of a diazonium salt reaction as a post-treatment method according to an embodiment of the present invention.
2 shows a simplified mechanism of a diazonium salt reaction and a radical reaction as a post-treatment method according to an embodiment of the present invention.
Figure 3 shows a brief mechanism of the Sonogashira coupling reaction as a post-treatment method according to one embodiment of the present invention.
Fig. 4 shows a brief mechanism of the Suzuki coupling reaction as a post-treatment method according to an embodiment of the present invention.
FIG. 5 shows a brief mechanism of a click coupling reaction as a post-treatment method according to an embodiment of the present invention.
FIG. 6 is a graph showing a result of comparing tensile test results of post-treated carbon nanotube fibers and untreated carbon nanotube fibers according to an embodiment of the present invention.
FIG. 7 is a graph comparing Raman spectrum test results of post-treated carbon nanotube fibers and non-post-treated carbon nanotube fibers according to an embodiment of the present invention.
FIG. 8 is a graph showing tensile strength data of carbon nanotube fibers according to reaction time of a diazonium salt reaction occurring in post treatment according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail.

The functional groups (1) and (2) used in the specification of the present invention should be understood as distinguishing functional groups only for convenience.

In the present invention, carbon nanotubes containing a halogen functional group (X) substituted for an aromatic compound attached to the surface of a carbon nanotube (CNT) are represented by X-Ph-CNT.

The present invention is a post-treatment method for improving the mechanical strength of carbon nanotube fibers composed of a plurality of carbon nanotubes.

Specifically, the carbon nanotube fiber post-treatment method for improving mechanical strength according to an embodiment of the present invention includes: preparing carbon nanotube fibers to prepare carbon nanotube fibers composed of carbon nanotubes; An aromatic compound adding step of adding an aromatic compound substituted with a plurality of functional groups (1) to the prepared carbon nanotube fibers; And a plurality of functional groups (1) of the added aromatic compound each react with one or more carbon nanotubes constituting the carbon nanotube fibers to form respective chemical bonds between the aromatic compound and the one or more carbon nanotubes A bond forming step; And a control unit.

According to the post-treatment method as described above, chemical cross-linking is formed between the individual carbon nanotubes constituting the carbon nanotube fibers, and thus the mechanical strength of the carbon nanotube fibers is remarkably improved finally.

First, carbon nanotube fibers, which is an aggregate of individual carbon nanotubes, are prepared in the preparation step of carbon nanotube fibers.

The carbon nanotube fibers are not limited as long as they have a one-dimensional or two-dimensional shape, and are aggregates of individual carbon nanotubes.

The carbon nanotubes are not particularly limited as long as the carbons connected in the form of a hexagonal ring are rolled into a nanometer-sized diameter and formed into a long barrel shape. The carbon nanotubes may have various mechanical and electrical properties depending on the arrangement of the hexagonal rings constituting the carbon nanotubes and the number of walls.

The carbon nanotube may include an aromatic compound attached to the surface of the carbon nanotube, and the aromatic compound may include a functional group (2). In one embodiment, a benzene ring having a functional group (2) may be attached on the surface of the carbon nanotube. The functional group (2) substituted on the benzene ring is not particularly limited, but alkyne, halogen halogen, or azide.

Next, in the aromatic compound addition step, aromatic compounds substituted with a plurality of functional groups (1) are added to the prepared carbon nanotube fibers.

In the aromatic compound substituted with the plurality of functional groups (1), the plurality of functional groups (1) are not particularly limited as long as they can form a chemical bond with the carbon nanotubes.

The plurality of functional groups 1 may be at least one functional group selected from the group consisting of an amine group, a halogen, an alkyne, a boric acid, and an azide, .

Particularly, in the case of the amine group (-NH ₂ ), a chemical reaction occurs with the surface of the carbon nanotube in a short period of time even at a temperature as low as about 60 ° C to form a strong covalent bond between the aromatic compound and the carbon nanotube It is preferable.

In particular, in the present invention, an aromatic compound includes a plurality of functional groups (1), wherein the plurality of functional groups (1) chemically react with different carbon nanotubes to form an aromatic compound When each of the carbon nanotubes is bonded to the carbon nanotubes, a strong covalent bond is formed between the carbon nanotubes, so that the mechanical strength of the carbon nanotube fibers is remarkably increased. In addition, when the plurality of functional groups (1) are all amine groups, a chemical reaction may occur simultaneously between the plurality of amine groups and different carbon nanotubes, so that a time for forming a strong covalent bond between the carbon nanotubes is shortened There is an effect that can be.

The aromatic compound is not particularly limited as long as it contains the plurality of functional groups (1). In one embodiment of the present invention, the aromatic compound may be a benzene ring. It is preferable that the plurality of functional groups (1) included in the aromatic compound are substituted in para form, and the individual carbon nanotubes may be arranged in a more compact form when crosslinking between individual carbon nanotubes is formed It is because. If the functional groups are substituted in the form of ortho or meta, it is disadvantageous that they can interfere with chemical bonding between individual carbon nanotubes due to steric hindrance.

In the subsequent bond formation step, a plurality of functional groups (1) possessed by the added aromatic compound are respectively reacted with one or more individual carbon nanotubes constituting the carbon nanotube fibers, and the aromatic compound and the individual carbon nanotubes To form a chemical bond.

The reaction for forming the chemical bond may be different depending on the functional group (1) substituted for the aromatic compound, the functional group (2) substituted for the aromatic compound attached on the surface of the individual carbon nanotube, and the like.

The present invention is illustrated by way of specific embodiments.

According to one embodiment of the present invention, carbon nanotube fibers composed of carbon nanotubes are prepared, then aromatic compounds substituted with a plurality of functional groups are added to the prepared carbon nanotube fibers, and a plurality of the aromatic compounds Wherein the functional groups of the carbon nanotubes react with one or more carbon nanotubes constituting the carbon nanotube fibers to form respective chemical bonds between the aromatic compound and the one or more carbon nanotubes, wherein the plurality of amine groups react with the one or more carbon nanotubes under temperature conditions of 50 to 100 ° C to form respective chemical bonds between the aromatic compound and the one or more carbon nanotubes . At this time, the reaction corresponds to a diazonium salt reaction (see FIG. 1). For example, the aromatic compound substituted with a plurality of amine groups may be 1,4-diaminobenzene. It is easy to form a chemical bond between the carbon nanotube fibers and the aromatic functional group substituted with the amine functional group under the above temperature conditions.

According to another embodiment of the present invention, carbon nanotube fibers composed of carbon nanotubes are prepared, aromatic compounds substituted with a plurality of functional groups are added to the prepared carbon nanotube fibers, and a plurality of the aromatic compounds Functional groups of the carbon nanotube fibers react with one or more carbon nanotubes constituting the carbon nanotube fibers to form respective chemical bonds between the aromatic compound and the one or more carbon nanotubes, wherein the amine group reacts with one carbon nanotube under a temperature condition of 50 to 70 ° C to form a chemical bond between the aromatic compound and the one carbon nanotube, Under a temperature condition (heat treatment condition) of 150 to 250 占 폚, reacts with another carbon nanotube to form an image Thereby forming a chemical bond between the aromatic compound and the other carbon nanotube. The reaction corresponds to a radical reaction through diazonium salt reaction and heat treatment (see FIG. 2). In one example, the one amine group and one halogen-substituted aromatic compound used may be 4-iodoaniline. It is easy to form a chemical bond between the carbon nanotube fiber and the amine functional substituted aromatic compound and a chemical bond between the carbon nanotube fiber and the halogen substituted aromatic compound under the respective temperature conditions.

According to another embodiment of the present invention, carbon nanotube fibers composed of carbon nanotubes are prepared, then aromatic compounds substituted with a plurality of functional groups are added to the prepared carbon nanotube fibers, A plurality of functional groups are respectively reacted with one or more carbon nanotubes constituting the carbon nanotube fibers to form respective chemical bonds between the aromatic compound and the one or more carbon nanotubes, Wherein the halogen is reacted with one or more carbon nanotubes under palladium or copper catalyst conditions to form respective chemical bonds between the aromatic compound and the one or more carbon nanotubes, Each containing an aromatic compound having an alkane group on its surface The alkane reacts with the halogen to form a chemical bond between the aromatic compound. At this time, the reaction corresponds to a Sonogashira coupling reaction (see FIG. 3). In one example, the plurality of halogen-substituted aromatic compounds used may be an Aryl-halide.

According to another embodiment of the present invention, carbon nanotube fibers composed of carbon nanotubes are prepared, then aromatic compounds substituted with a plurality of functional groups are added to the prepared carbon nanotube fibers, A plurality of functional groups each react with one or more carbon nanotubes constituting the carbon nanotube fibers to form respective chemical bonds between the aromatic compound and the one or more carbon nanotubes, wherein the plurality of functional groups are all boric acid wherein the boric acid reacts with one or more carbon nanotubes under palladium catalyst conditions to form respective chemical bonds between the aromatic compound and the one or more carbon nanotubes, The tubes each contain an aromatic compound having a halogen group on its surface, The halogen is reacted with the boric acid to form a chemical bond between the aromatic compounds. At this time, the reaction corresponds to a Suzuki coupling reaction (see FIG. 4). For example, the plurality of boric acid-substituted aromatic compounds used may be Aryl-boric acid.

According to another embodiment of the present invention, carbon nanotube fibers composed of carbon nanotubes are prepared, then aromatic compounds substituted with a plurality of functional groups are added to the prepared carbon nanotube fibers, A plurality of functional groups are respectively reacted with one or more carbon nanotubes constituting the carbon nanotube fibers to form respective chemical bonds between the aromatic compound and the one or more carbon nanotubes, wherein the alkyne reacts with one or more carbon nanotubes under Cu (I) catalyst conditions to form respective chemical bonds between the aromatic compound and the one or more carbon nanotubes, The one or more carbon nanotubes each include an aromatic compound having an azide group on its surface, The reaction with the azide group and alkyne to form a chemical bond between the aromatic compound. The reaction corresponds to a click coupling reaction (see FIG. 5). For example, the plurality of alkane-substituted aromatic compounds used may be arylalkyne.

According to the present invention, since carbon nanotube fibers post-treated by the above-described method have strong covalent bonds between individual carbon nanotubes constituting the carbon nanotube fibers, mechanical properties thereof are remarkably higher than those of conventional carbon nanotube fibers There is an ascending effect. In addition, the reactions can be carried out at a relatively low temperature, and the reaction takes place in a short time (about 5 minutes or less), which is suitable for large-scale production. Further, if physical focusing is possible by the solvent used in the post-treatment, it is possible to produce fibers having higher physical properties.

[Example]

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are only for illustrating the present invention and that the scope of the present invention is not construed as being limited by these embodiments.

Example  One

A method for post-treatment of carbon nanotube fibers using an aromatic compound substituted with two amine groups is as follows.

50 ml of sulfuric acid, 0.8 g of p-phenylenediamine and 0.25 g of sodium nitrite are mixed at 60 ° C for 1 hour. This reaction is carried out in a nitrogen atmosphere so that the radicals produced in this process are not removed by contact with moisture or air. Carbon nanotube fibers are impregnated into the prepared solution for 5 minutes. In order to remove the diazonium salt solution present in the carbon nanotube fibers, the fibers are impregnated with DMF at room temperature for 30 minutes and impregnated in ethanol at room temperature for 1 hour to remove DMF present in the fibers. Finally, it is dried in a vacuum oven at 60 DEG C for 24 hours (see Fig. 1).

Example  2

A method for post-treatment of carbon nanotube fibers using an aromatic compound substituted with one amine group and one iodine (halogen) atom is as follows.

50 ml of sulfuric acid, 0.8 g of 4-iodoaniline and 0.25 g of sodium nitrite are mixed at 60 ° C for 1 hour. This reaction is carried out in a nitrogen atmosphere so that the radicals produced in this process are not removed by contact with moisture or air. Carbon nanotube fibers are impregnated into the prepared solution for 5 minutes. In order to remove the diazonium salt solution present in the carbon nanotube fibers, the fibers are impregnated with DMF at room temperature for 30 minutes and impregnated in ethanol at room temperature for 1 hour to remove DMF present in the fibers. Finally, the carbon nanotube fiber is dried in a vacuum oven at 60 ° C. for 24 hours to prepare an aromatic functional group substituted with iodine introduced on the surface of the carbon nanotube. In addition, iodine-eliminated radicals are reacted with each other to form cross-linking between the carbon nanotubes, and the carbon nanotubes to which the iodine-substituted aromatic functional group is introduced are treated at 200 ° C for 10 minutes (see FIG. 2).

Comparative Example  One

Carbon nanotube fibers not subjected to the post-treatment process were prepared.

As a material to supply carbon, which is a main constituent of carbon nanotubes, in a vertical type electric furnace at 1,130 ~ 1,250 ℃, ethanol or acetone and 0.1 ~ 2.5 wt% of ferrocene as a catalyst acting as a base material for growth of carbon nanotubes, The solution was sonicated for 2 hours at a rate of 5 ~ 25 ml / h. The hydrogen gas was then injected at a rate of 800 ~ 1600 sccm. The carbon nanotubes are synthesized inside the electric furnace. The mixture was passed through a water tank under an electric furnace, treated with DMSO, and passed through a dryer at a temperature of 200 ° C to produce carbon nanotube fibers.

Experiment 1

In order to confirm the effect of crosslinking formation between carbon nanotubes on the mechanical properties of carbon nanotube fibers through a diazonium salt reaction using an aromatic compound substituted with two amine groups, the carbon nanotubes prepared in Example 1 and Comparative Example 1 The results of confirming the tensile strength of the tube fibers are shown in Table 1. The tensile strength and modulus values were estimated by a universal testing machine (UTM, 5567A, Instron. USA).

<Changes in Mechanical Properties of Carbon Nanotube Fibers due to Cross-Linking Between Carbon Nanotubes> division Sample name The tensile strength  (N / tex ) Example 1 Crosslinked carbon nanotube fibers 0.60 + - 0.12 Comparative Example 1 Pure carbon nanotube fiber 0.38 + 0.08

As shown in Table 1, when carbon nanotube fibers crosslinked between carbon nanotubes are produced using the present invention, it is possible to produce carbon nanotube fibers having an improved tensile strength by 60% as compared with pure carbon nanotube fibers . When the diazonium salt reaction of the carbon nanotube fibers is performed using the aromatic compound substituted with two amine groups through the present invention, crosslinking, that is, strong chemical bonding is induced between the carbon nanotubes or the carbon nanotube bundles constituting the fibers It is possible to fabricate high strength carbon nanotube fibers that more effectively disperses the tensile force applied to the fibers by complementing the weak bonding force by the original van der Waals bonding.

Experiment 2

In order to confirm the effect of diazonium salt reaction using one amine group and one iodine atom-substituted aromatic compound and formation of cross-linking between carbon nanotubes through heat treatment on the mechanical properties of carbon nanotube fibers, The results of confirming the tensile strength, elastic modulus and elongation of the carbon nanotube fibers produced in Table 1 are shown in Table 2. The tensile strength and modulus values were estimated by a universal testing machine (UTM, 5567A, Instron. USA).

The ratio of the G-band to the D-band in the Raman analysis of the carbon nanotube fibers prepared in Example 2 and Comparative Example 1 was measured and shown in Table 3. In this experiment, Raman spectroscopy was used.

<Changes in Mechanical Properties of Carbon Nanotubes due to Cross-Linking Between Carbon Nanotubes> division Sample name The tensile strength  (N / tex ) The elastic modulus (N / tex ) Elongation  (%) Example 2 Heat treated I-Ph-carbon nanotube fibers 0.61 + - 0.10 55.21 + - 13.06 3.40 ± 1.01 Comparative Example 1 Pure carbon nanotube fiber 0.22 0.02 19.59 ± 1.75 12.71 ± 0.82

As in Experimental Example 1, when carbon nanotube fibers crosslinked between carbon nanotubes were produced using the present invention as shown in Table 2, carbon nanotube fibers having a tensile strength increased by up to 180% as compared with pure carbon nanotube fibers It can be seen that tube fibers can be made. In the present invention, an aromatic functional group substituted with iodine is introduced into a carbon nanotube fiber using an aromatic compound substituted with one amine group and one iodine atom, and the radicals of the individual carbon nanotubes generated through the heat treatment are reacted with each other, The carbon nanotubes or the carbon nanotube bundles constituting the carbon nanotube bundle are induced to induce a strong crosslinking so that the weak binding force due to the original van der Waals bonding can be compensated to produce a high strength carbon nanotube fiber that more effectively disperses the tensile force applied to the fibers .

&Lt; Analysis for confirming carbon nanotube functional group introduction and cross-linking formation by diazonium salt reaction and heat treatment > division Sample name Raman
( I _G / I _D ) * Elemental content (%) C O N S I Example 2 I-Ph-carbon nanotube fibers 2.65 82.41 13.36 1.32 0.69 0.02 Heat-treated
I-Ph-carbon nanotube fibers 2.22 75.30 16.57 1.02 1.67 0.00 Comparative Example 1 Pure carbon nanotube fiber 3.34 92.14 5.01 1.15 0.12 0.00

* I _G / I _D : Comparison between G-band and D-band in Raman analysis

As shown in Table 3, the ratio of the G-band and the D-band in the Raman analysis decreased as the diamonium salt reaction and heat treatment of the carbon nanotube fibers proceeded. As a result, the hexagonal ring structure originally possessed by the carbon nanotubes And the functional group is introduced on the surface of the carbon nanotube. As shown in Table 3, the elemental analysis by XPS revealed that the iodine atoms introduced due to the diazonium salt reaction fell off through the heat treatment, that is, the radicals of the respective carbon nanotubes produced thereby resulted in crosslinking formation It is understood that it is involved.

Experiment 3

Table 4 shows the tensile strengths of the carbon nanotube fibers prepared in Example 1 and Comparative Example 1 in order to confirm the change in mechanical properties of the carbon nanotube fibers according to the reaction time of the diazonium salt. The tensile strength and modulus values were estimated by a universal testing machine (UTM, 5567A, Instron. USA).

<Changes in Mechanical Properties of Carbon Nanotube Fibers according to Diazonium Salt Reaction Time> division Sample name Reaction time ( min ) The tensile strength  (N / tex ) Example 1 Crosslinked carbon nanotube fibers One 0.43 + 0.07 5 0.60 + - 0.12 20 0.59 + 0.11 30 0.56 + 0.11 60 0.49 ± 0.09 120 0.39 + - 0.05 Comparative Example 1 Pure carbon nanotube fiber 0 0.38 + 0.08

As shown in Table 4, the highest tensile strength value of 0.60 N / tex was obtained when the reaction time of the diazonium salt of the pure carbon nanotube fiber for crosslinking was 5 minutes. However, after 5 minutes elapsed, the reaction solution penetrated deeply into the fibers did not participate in the formation of crosslinking, and one amine group reacted The hydrophilic amine groups push the hydrophobic carbon nanotubes to increase the distance between the nanotubes. Therefore, it is considered that the original van der Waals bonds, which were weakly existing, are destroyed and the tensile strength is lowered.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. something to do. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (9)

Preparing a carbon nanotube fiber comprising carbon nanotube fibers;
An aromatic compound addition step of providing a plurality of functional group-substituted aromatic compounds selected from the group consisting of an amine group and a halogen, sulfuric acid, and sodium nitrite to the carbon nanotube fibers; And
A plurality of functional groups of the aromatic compound react with one or more carbon nanotubes constituting the carbon nanotube fibers to form a chemical bond between the aromatic compound and the one or more carbon nanotubes; Wherein the carbon nanotube fiber after treatment is a carbon nanotube fiber. delete The method according to claim 1,
The plurality of functional groups are all amine groups,
Wherein the plurality of amine groups react with the one or more carbon nanotubes to form a chemical bond between the aromatic compound and the one or more carbon nanotubes under a temperature condition of 50 to 100 ° C. A method for post - treatment of carbon nanotube fibers for strength improvement. The method according to claim 1,
Wherein the plurality of functional groups are an amine group and a halogen,
The amine group reacts with one or more carbon nanotubes to form a chemical bond between the aromatic compound and the one or more carbon nanotubes under a temperature condition of 50 to 70 ° C,
Wherein the halogen is reacted with another one or more carbon nanotubes under a temperature condition of 150 to 250 ° C to form a chemical bond between the aromatic compound and the other one or more carbon nanotubes. Fiber post treatment method. The method according to claim 1,
Wherein the plurality of functional groups are all halogen,
Wherein the halogen is reacted with one or more carbon nanotubes under palladium or copper catalyst conditions to form a chemical bond between the aromatic compound and the one or more carbon nanotubes,
Wherein the at least one carbon nanotube includes an aromatic compound having an alkane group on the surface thereof to form a chemical bond between the alkane and the halogen to form a chemical bond between the aromatic compound and the carbon nanotube fiber Post treatment method. Preparing a carbon nanotube fiber comprising carbon nanotube fibers;
Adding an aromatic compound substituted with a plurality of functional groups to the carbon nanotube fibers, wherein the plurality of functional groups are all boric acid; And
Wherein the boric acid reacts with one or more carbon nanotubes constituting the carbon nanotube fibers under a palladium catalyst to form a chemical bond between the aromatic compound and the one or more carbon nanotubes, A step of forming a bond including an aromatic compound having a halogen group in the halogen atom, wherein the halogen reacts with the boric acid to form a chemical bond between the aromatic compound; Wherein the carbon nanotube fiber after treatment is a carbon nanotube fiber. Preparing a carbon nanotube fiber comprising carbon nanotube fibers;
Adding an aromatic compound substituted with a plurality of functional groups to the carbon nanotube fibers, wherein the plurality of functional groups are all alkyne; And
Wherein the alkane reacts with one or more carbon nanotubes constituting the carbon nanotube fibers under Cu (I) catalyst conditions to form a chemical bond between the aromatic compound and the one or more carbon nanotubes, The nanotube includes an aromatic compound having an azide group on its surface, and the azide and the alkane react to form a chemical bond between the aromatic compounds; Wherein the carbon nanotube fiber after treatment is a carbon nanotube fiber. 8. The method according to any one of claims 1 to 7,
Wherein the aromatic compound is benzene. &Lt; RTI ID = 0.0 &gt; 8. &lt; / RTI &gt; 8. Carbon nanotube fibers which are post-treated by the process according to any one of claims 1 to 7.

Images