TWI419921B - Method for making carbon nanotube composite structure - Google Patents

Description

Method for preparing nano carbon tube composite structure

The invention relates to a preparation method of a carbon nanotube composite structure.

The carbon nanotube is a hollow tube rolled from a graphene sheet. Nano carbon tubes have excellent mechanical, thermal and electrical properties and are used in a wide range of applications. For example, carbon nanotubes can be used to make field effect transistors, atomic force microscope tips, field emission electron guns, nano templates, and the like. The application of the carbon nanotubes in the above technology is mainly the application of the carbon nanotubes on the microscopic scale, and the operation is difficult. Therefore, it is of great significance to make the carbon nanotubes have a macroscopic structure and to be applied at a macroscopic level.

In 2002, Jiang Kaili and others successfully extracted a nanometer carbon pipeline with a macroscopic scale from a carbon nanotube array, see "Spinning Continuous Carbon Nanotube Yarns", Nature, V419, P801. The nanocarbon pipeline is composed of a plurality of carbon nanotubes connected end to end and arranged in a preferred orientation along the same direction.

However, the bonding force between the carbon nanotubes in the nanocarbon pipeline is weak, so the mechanical properties of the nanocarbon pipeline need to be further improved.

In view of this, it is necessary to provide a method for preparing a carbon nanotube composite structure having good mechanical properties.

A method for preparing a carbon nanotube composite structure, comprising the steps of: providing a carbon nanotube structure, wherein the carbon nanotube structure comprises a plurality of carbon nanotubes connected by van der Waals; the carbon nanotube a composite-polymer in the structure; and a graphitized polymer compounded in the carbon nanotube structure to graphitize the polymer into a graphite structure.

In contrast to the prior art, the preparation method fills and composites a graphite structure in the carbon nanotube structure by graphitizing a polymer compounded in the carbon nanotube structure. The graphite structure can be bonded to the carbon nanotube structure through carbon-carbon bonds, thereby improving the bonding force between the carbon nanotubes and the excellent mechanical properties of the carbon nanotube composite structure.

Figure 1 is a scanning electron micrograph of a carbon nanotube film.

Figure 2 is a scanning electron micrograph of a carbon nanotube rolled film.

Figure 3 is a scanning electron micrograph of a carbon nanotube film.

Figure 4 is a scanning electron micrograph of a carbon nanotube cross film.

Figure 5 is a scanning electron micrograph of a non-twisted nanocarbon pipeline.

Figure 6 is a scanning electron micrograph of a twisted nanocarbon line.

The invention will be further described in detail below with reference to the accompanying drawings.

The embodiment of the present invention provides a method for preparing a carbon nanotube composite structure, which specifically includes the following steps: Step S10, providing a carbon nanotube structure, the carbon nanotube structure including a plurality of carbon nanotubes passing through the van der Waals Van der Waals attractive force connection; Step S20, compounding a polymer in the carbon nanotube structure; and step S30, graphitizing the polymerized carbon nanotube structure to graphitize the polymer into a graphite structure.

In step S10, the carbon nanotube structure is composed of a plurality of carbon nanotubes connected to each other by a van der Waals force to form a carbon nanotube skeleton, and the carbon nanotube skeleton may be a membrane structure or a linear structure. Structure or other shape structure. The carbon nanotube structure is a self-supporting structure of a carbon nanotube, and the so-called "self-supporting" means that the carbon nanotube structure does not need to be supported by being disposed on a surface of the substrate, that is, the edge or the opposite end is not supported. The rest of the part can maintain its own specific shape. Since a large number of carbon nanotubes in the self-supporting carbon nanotube structure are attracted to each other by van der Waals force, the carbon nanotube structure has a specific shape to form a self-supporting structure. Generally, the number of carbon nanotubes in the self-supporting carbon nanotube structure between 0.2 nm and 9 nm is large, and the portion of the carbon nanotubes has a large van der Waals force. So that the carbon nanotube structure can form a self-supporting structure only by van der Waals force.

The carbon nanotube structure may include a carbon nanotube membrane structure, and the carbon nanotube membrane structure is a membrane-like structure having a plurality of micropores. The micropores are formed by interconnecting a plurality of carbon nanotubes by van der Waals force, and the carbon nanotubes forming the micropores may be in the same plane or in different planes. The size of the micropores is between 1 nm and 500 nm. The structure of the carbon nanotube membrane structure is not limited, and only a plurality of the above micropores can be formed. Preferably, the carbon nanotube membrane structure may be a self-supporting structure such that the carbon nanotube membrane structure can serve as a skeleton of the carbon nanotube composite structure. The so-called "self-supporting" means that the carbon nanotube film structure can maintain its own specific shape without being disposed on a surface of a substrate. Since the self-supporting carbon nanotube membrane structure comprises a large number of carbon nanotubes attracted to each other by van der Waals force, the carbon nanotube membrane structure is specific The shape forms a self-supporting structure.

The carbon nanotube membrane structure may include at least one carbon nanotube membrane, and when the carbon nanotube membrane structure comprises a plurality of carbon nanotube membranes, the plurality of carbon nanotube membranes are stacked, adjacent to each other The carbon nanotube membranes are combined by van der Waals force.

Referring to FIG. 1, the carbon nanotube film can be a carbon nanotube flocculation membrane, and the carbon nanotube membrane is obtained by flocculation treatment of a carbon nanotube raw material, such as a super-aligned array. A self-supporting carbon nanotube film. The carbon nanotube flocculation membrane comprises carbon nanotubes which are intertwined and uniformly distributed. The length of the carbon nanotubes is greater than 10 microns, preferably from 200 microns to 900 microns, such that the carbon nanotubes are intertwined with one another. The carbon nanotubes are attracted to each other by van der Waals forces to form a network structure. Since the large number of carbon nanotubes in the self-supporting carbon nanotube flocculation membrane are mutually attracted and intertwined by van der Waals force, the carbon nanotube flocculation membrane has a specific shape to form a self-supporting structure. . The carbon nanotube flocculation membrane is isotropic. The carbon nanotubes in the carbon nanotube flocculation membrane are uniformly distributed and randomly arranged to form a plurality of gaps or micropores having a size ranging from 1 nm to 500 nm. The area and thickness of the carbon nanotube flocculation membrane are not limited, and the thickness is approximately between 0.5 nm and 100 μm.

The carbon nanotube film may be a carbon nanotube rolled film, which is a self-supporting carbon nanotube film obtained by rolling a carbon nanotube array. The carbon nanotube rolled film comprises uniformly distributed carbon nanotubes, and the carbon nanotubes are arranged in the same direction or in different directions. The carbon nanotubes in the carbon nanotube rolled film partially overlap each other and are attracted to each other by the van der Waals force, and the carbon nanotube film has good flexibility and can be bent and folded into Any shape without breaking. Moreover, since the carbon nanotubes in the carbon nanotube rolled film are attracted to each other by the van der Waals force, the carbon nanotube film is a self-supporting structure. The nanocarbon The carbon nanotubes in the tube-rolled film form an angle β with the surface of the growth substrate forming the carbon nanotube array, wherein β is greater than or equal to 0 degrees and less than or equal to 15 degrees, and the angle β is applied to the carbon nanotubes The pressure on the array is related. The larger the pressure, the smaller the angle. Preferably, the carbon nanotubes in the carbon nanotube rolled film are aligned parallel to the growth substrate. The carbon nanotube rolled film is obtained by rolling a carbon nanotube array, and the carbon nanotubes in the carbon nanotube rolled film have different arrangement forms according to the manner of rolling. Specifically, the carbon nanotubes can be arranged in disorder; referring to FIG. 2, when rolling in different directions, the carbon nanotubes are arranged in different directions; when crushed in the same direction, the carbon nanotubes are along a The orientation is preferred and the orientation is preferred. The length of the carbon nanotubes in the carbon nanotube rolled film is greater than 50 microns. The area of the carbon nanotube rolled film is substantially the same as the size of the carbon nanotube array. The thickness of the carbon nanotube film is related to the height of the carbon nanotube array and the pressure of the rolling, and may be between 0.5 nm and 100 μm. It can be understood that the larger the height of the carbon nanotube array and the lower the pressure applied, the greater the thickness of the prepared carbon nanotube rolled film; on the contrary, the smaller the height of the carbon nanotube array, the more the applied pressure Large, the smaller the thickness of the prepared carbon nanotube rolled film. a gap between adjacent carbon nanotubes in the carbon nanotube film, thereby forming a plurality of gaps between 1 nm and 500 nm in the carbon nanotube film Or micropores.

The carbon nanotube film may be a carbon nanotube film, and at this time, the carbon nanotube film structure comprises at least two layers of carbon nanotube film. Referring to FIG. 3, the formed carbon nanotube film is a self-supporting structure composed of a plurality of carbon nanotubes. The plurality of carbon nanotubes are arranged in a preferred orientation along the length of the carbon nanotube film. The preferred orientation means that the overall extension direction of most of the carbon nanotubes in the carbon nanotube film is substantially in the same direction. Moreover, the overall extension direction of the majority of the carbon nanotubes is substantially parallel to the surface of the carbon nanotube film. Further, most of the carbon nanotubes in the carbon nanotube film are drawn It is connected end to end by Van der Waals. Specifically, each of the carbon nanotubes of the majority of the carbon nanotubes extending substantially in the same direction in the carbon nanotube film is connected end to end with the carbon nanotubes adjacent in the extending direction by van der Waals force . Of course, there are a few carbon nanotubes in the carbon nanotube film that deviate from the extending direction. These carbon nanotubes do not constitute an obvious alignment of the majority of the carbon nanotubes in the carbon nanotube film. influences. The self-supporting carbon nanotube film does not need a large-area carrier support, but only provides support force on both sides, and can be suspended in the whole to maintain its own film state, that is, the carbon nanotube film is placed (or When fixed on two supports arranged at a certain distance, the carbon nanotube film located between the two supports can be suspended to maintain its own film state. The self-supporting is mainly achieved by the presence of a continuous carbon nanotube in the carbon nanotube film which is continuously arranged by van der Waals. Specifically, the majority of the carbon nanotubes extending substantially in the same direction in the carbon nanotube film are not absolutely linear and may be appropriately bent; or are not completely aligned in the extending direction, and may be appropriately deviated from the extending direction. . Therefore, it may not be possible to exclude partial contact between the carbon nanotubes juxtaposed in the majority of the carbon nanotubes extending substantially in the same direction.

Specifically, the carbon nanotube film comprises a plurality of continuous and aligned carbon nanotube segments. The plurality of carbon nanotube segments are connected end to end by van der Waals force. Each carbon nanotube segment consists of a plurality of carbon nanotubes that are parallel to each other. The carbon nanotube segments have any length, thickness, uniformity, and shape. The carbon nanotube film has good light transmittance and the visible light transmittance can reach more than 75%.

When the carbon nanotube film structure comprises a multi-layered carbon nanotube film, a preferred angle between the adjacent two layers of carbon nanotube film forming a cross angle α, α is greater than or equal to 0 degrees is less than or equal to 90 degrees (0° α 90°). Referring to FIG. 4, preferably, to increase the strength of the carbon nanotube film, the intersection angle α is approximately 90. Degree, that is, the arrangement direction of the carbon nanotubes in the adjacent two layers of carbon nanotube film is substantially perpendicular to form a cross film. There is a gap between the adjacent carbon nanotube film or between adjacent carbon nanotubes in a carbon nanotube film, thereby forming a plurality of uniform distributions in the carbon nanotube structure, without rules Arranged, with a size between 1 nm and 500 nm or a micropore.

The carbon nanotube structure may include at least one nanocarbon pipeline structure, and when the carbon nanotube structure includes a plurality of nanocarbon pipeline structures, the plurality of carbon nanotube pipelines may be disposed in parallel, wound or braided with each other. The nanocarbon pipeline structure includes at least one nanocarbon pipeline including a plurality of carbon nanotubes interconnected by van der Waals and extending substantially along an axial direction of the nanocarbon pipeline. When the nanocarbon line structure includes a plurality of nanocarbon lines, the plurality of carbon carbon lines may be disposed in parallel or wound with each other. The structure of the nanocarbon pipeline is not limited. Preferably, the nanocarbon pipeline is a self-supporting structure. The so-called "self-supporting" means that the nanocarbon pipeline can maintain its own specific shape without being disposed on a surface of a substrate. Since a large number of carbon nanotubes in the self-supporting nanocarbon pipeline are attracted to each other by van der Waals force, the nanocarbon pipeline structure has a specific shape to form a self-supporting structure. Typically, there is a large van der Waals force between the carbon nanotubes in the nanocarbon line such that the carbon nanotube film structure forms the self-supporting structure only by van der Waals. When the nanocarbon pipeline structure comprises a plurality of carbon nanotubes, the plurality of carbon nanotubes may be arranged in parallel or wound with each other, and the adjacent nanocarbon pipelines are connected to the van der Waals force.

The nano carbon pipeline may be a wire structure formed by processing a carbon nanotube film, and the treatment method of the carbon nanotube film comprises a volatile organic solvent infiltration treatment or a mechanical torsion treatment. The volatile organic solvent infiltration treatment may drip the organic solvent on the surface of the carbon nanotube film by a test tube to infiltrate the entire carbon nanotube film, or The above-mentioned fixing frame in which the carbon nanotube film is formed may be entirely immersed in a container containing an organic solvent to be infiltrated. The volatile organic solvent is ethanol, methanol, acetone, dichloroethane or chloroform, and ethanol is used in this embodiment. The tension generated by the organic solvent upon volatilization causes the carbon nanotube film to shrink to form the nanocarbon line. Referring to FIG. 5, the nano carbon line obtained by the volatile organic solvent infiltration treatment is a non-twisted nano carbon line, and the non-twisted nano carbon line includes a plurality of nano carbons arranged along the length of the nano carbon line. tube. Specifically, the non-twisted nanocarbon pipeline includes a plurality of carbon nanotubes connected end to end by van der Waals force and arranged in an axially preferred orientation along the nanocarbon pipeline. The mechanical torsion treatment may be performed by twisting both ends of the carbon nanotube film in the opposite direction by using a mechanical force. Referring to FIG. 6, the nano carbon line obtained by the mechanical torsion treatment is a twisted nano carbon line, and the twisted nano carbon line includes a plurality of carbon nanotubes arranged in an axial spiral arrangement around the carbon carbon line. Specifically, the twisted nanocarbon pipeline includes a plurality of carbon nanotubes connected end to end by van der Waals force and extending helically along the axial direction of the carbon nanotubes. It can be understood that the twisted nanocarbon pipeline can also be obtained by simultaneously or sequentially performing an organic solvent volatile organic solvent wetting treatment or a mechanical torsion treatment on the obtained carbon nanotube film.

In the step S20, the method of compounding the polymer in the carbon nanotube structure is not limited, and only the polymer can be compounded with the plurality of carbon nanotubes in the carbon nanotube structure, and It is sufficient to form a complex covalent bond between the plurality of carbon nanotubes and the polymer. Specifically, the method of compounding the carbon nanotube structure with a polymer may further include the step of: S21, impregnating the carbon nanotube structure in a polymer solution to recombine with the polymer.

In step S21, the polymer solution can be obtained by directly melting the polymer or dissolving the polymer in a solvent. In this embodiment, the polymer The solution is obtained by dissolving the polymer in an organic solvent. The type and nature of the polymer are not limited and can be selected according to actual needs. The polymer may include polyacrylonitrile (PAN), polyvinyl alcohol (PVA), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC). And any one or any combination of polyethylene terephthalate (PET). The degree of polymerization of the polymer can also be selected according to the actual operation. Preferably, the degree of polymerization of the polymer is between 1500 and 3500 such that the polymer is both soluble and maintains a certain wettability with the carbon nanotubes. The percentage by mass of the polymer in the polymer solution varies depending on the polymer and the organic solvent. Generally, the percentage of the polymer in the polymer solution is approximately between 1% and 9%. The organic solvent is used to dissolve the polymer and is capable of being wetted with the carbon nanotubes, thereby enabling the polymer to be sufficiently compounded into the carbon nanotube structure or even composited to the carbon nanotube Inside the carbon nanotubes in the structure. Preferably, the organic solvent has a large surface tension while being capable of dissolving the polymer. Specifically, an organic solvent having a surface tension greater than 20 millinewtons per meter and a contact angle to the carbon nanotubes of less than 90 degrees can be selected. The organic solvent may include Dimethyl Sulphoxide (DMSO), Dimethyl Formamide (DMF), 2,5-dimethyl furan, and N- Any one or combination of N-methyl-2-pyrrolidone (NMP). Since the dissolving power of the organic solvent varies depending on the polymer, the selection of the organic solvent is also selected depending on the specific polymer. For example, when the polymer is polyvinyl alcohol, the organic solvent may be selected from dimethyl hydrazine. The surface tension of the dimethyl hydrazine is approximately 43.54 milli-Nilometers per meter and the contact angle to the carbon nanotubes is approximately 110 degrees. The organic solvent to the carbon nanotube The smaller the contact angle, the better the wettability of the polymer to the carbon nanotube structure, and the closer the polymer binds to the carbon nanotube structure. The greater the surface tension of the organic solvent, the better the wettability of the polymer to the carbon nanotube structure, the stronger the ability to shrink the structure of the carbon nanotube, the polymer and the naphthalene The tighter the carbon nanotube structure is combined.

When the carbon nanotube structure is a carbon nanotube film structure, after the polymer solution infiltrates the carbon nanotube film structure, a part of the polymer solution will penetrate into the structure of the carbon nanotube film. The pores are in contact with the carbon nanotubes in the carbon nanotube membrane structure. After the organic solvent in the polymer solution is evaporated, the polymer therein will be in intimate contact with the carbon nanotube and form a covalent bond. Moreover, after the polymer solution fills the micropores, two layers of polymer solution may be formed on opposite surfaces of the carbon nanotube film structure. After the organic solvent in the polymer solution layer is evaporated, two polymer layers will be formed on the two surfaces and the carbon nanotube film structure is sandwiched therein to form a layered structure.

When the carbon nanotube structure includes at least one nanocarbon pipeline structure, the polymer solution penetrates into a gap in the nanocarbon pipeline structure and is in combination with nanocarbon in the nanocarbon pipeline structure Tube infiltration. After the organic solvent in the polymer solution is evaporated, the polymer in the polymer solution will wrap or coat the carbon nanotubes connected end to end in the nanocarbon pipeline structure to form a plurality of polymer fibers, or fill up The gaps in the nanocarbon line structure form a unitary polymer structure.

In step S20, the carbon nanotube structure may also be compounded with a polymer by in-situ polymerization. Specifically, the method of compounding the carbon nanotube structure with a polymer may further include the steps of: S121, impregnating the carbon nanotube structure in a polymer monomer solution; and S122, making the polymer The monomer generates a polymerization reaction, which After polymerization of the polymer monomer, the polymer is combined with the carbon nanotube structure.

In steps S121 and S122, the polymer monomer may include acrylonitrile, vinyl alcohol, propylene, styrene, vinyl chloride or ethylene terephthalate. The polymer monomer is polymerized to form polyacrylonitrile, polyvinyl alcohol, polypropylene, polystyrene, polyvinyl chloride or polyethylene terephthalate.

The solubility of the polymer monomer in the same organic solvent is greater than the solubility of the polymer corresponding to the polymer monomer in the organic solvent. Therefore, the method of compounding the carbon nanotube structure with a polymer by in-situ polymerization is performed by directly impregnating the carbon nanotube structure in the polymer solution to make the polymer and the nanometer. The carbon tube structure composite method enables a wider selection of the polymer.

In the step S30, the method of graphitization is not limited, and only the polymer compounded in the carbon nanotube structure can be formed into a graphite structure without destroying the carbon nanotube structure. Specifically, the method for graphitizing may include the following steps: S31, heating the polymerized carbon nanotube structure in air to pre-oxidize the polymer; and S32, pre-oxidizing The polymer is placed in a vacuum environment or an inert gas atmosphere for high temperature graphitization.

In step S31, the pre-oxidation temperature is approximately between 200 and 300 degrees.

In step S32, the vacuum environment or inert gas environment is used to obtain a low oxygen or anaerobic environment such that the carbon nanotube structure is not oxidized at high temperatures. When a vacuum environment is selected, the atmospheric pressure in the vacuum environment is less than 5*10 ^-2 Pa, preferably, the atmospheric pressure in the vacuum environment is less than 5*10 ^-5 Pa. When an inert gas atmosphere is selected, the inert gas includes argon gas, nitrogen gas, or the like.

The polymer compounded in the carbon nanotube structure removes most of the nitrogen, hydrogen and oxygen during the graphitization process to form the graphite structure. And a plurality of carbon-carbon bonds are formed between the graphite structure and the carbon nanotube structure during the graphitization process, and the graphite structure is combined with the carbon nanotube structure to form the carbon nanotube composite structure. The carbon-carbon bond may be formed either by carbonizing the covalent bond or by recombining carbon atoms in the graphite structure with carbon atoms in the carbon nanotube structure at a high temperature. The carbon-carbon bond includes an sp ² or sp ³ bond formed between carbon-carbon atoms. Specifically, the carbon-carbon bond includes an sp ² or sp ³ bond formed between carbon-carbon atoms. In the carbon nanotube composite structure, since the carbon nanotube structure is a self-supporting structure, the carbon nanotube structure is a carbon nanotube skeleton formed by interconnecting a plurality of carbon nanotubes by van der Waals force. And the graphite structure is filled in the carbon nanotube skeleton, and is tightly bonded to the carbon nanotube skeleton by a carbon-carbon bond and a van der Waals force.

The specific form of the graphite structure is related to the specific process at the time of graphitization. For example, the temperature of high temperature graphitization is usually above 2000 degrees. In order to achieve different graphitization effects, the time to heat to the temperature can be selected according to actual needs. When the heating rate is fast, the polymer is easily graphitized into graphite fragments. The graphite segment includes at least one graphene (Graphene), and when the graphite segment includes a plurality of graphenes, the plurality of graphenes are bonded by carbon-carbon bonds. The carbon-carbon bond includes an sp2 or sp3 bond formed between carbon-carbon atoms. Specifically, the carbon-carbon bond includes an sp2 or sp3 bond formed between carbon-carbon atoms. When the heating rate is slow, the polymer is easily graphitized into graphite fibers. The graphite fibers are formed by removing most of the nitrogen, hydrogen, and oxygen from the polymer fibers. The graphite fiber is also called a high modulus carbon fiber, and the graphite fiber is a fiber having a molecular structure that has been graphitized and has a layered hexagonal lattice graphite structure with a carbon content of 99% or more.

The specific form of the graphite structure is also related to the structure of the carbon nanotube structure. When the carbon nanotube structure includes a plurality of micropores, the polymer is easily graphitized into a plurality of graphite fragments. When the carbon nanotube structure comprises a plurality of complex carbon nanotubes connected end to end and extending substantially in the same direction, the polymer is easily graphitized into a plurality of graphite fibers.

Specifically, when the carbon nanotube structure includes at least one carbon nanotube film structure, the polymer filled in the micropores of the carbon nanotube film structure is graphitized into graphite fragments. Adjacent graphite segments are bonded by carbon and carbon to form the graphite structure. The graphite fragments filled in the micropores of the carbon nanotube membrane structure do not necessarily completely fill the micropores. Usually, the plurality of graphite fragments are attached to the wall of the carbon nanotube or coated with A portion of the surface of the carbon nanotube is bonded to the carbon nanotube by a carbon-carbon bond. That is, the carbon nanotube composite structure formed by the composite of the carbon nanotube film structure and the graphite structure is basically composed of a carbon nanotube and a graphite segment, and the carbon nanotube and the graphite segment pass through a carbon-carbon bond. Get the combination of Wahli.

When the carbon nanotube film structure has two polymer layers on opposite surfaces, the polymer layer forms two graphite layers on both sides of the carbon nanotube film structure after graphitization, thereby forming a A carbon nanotube composite structure having a layered structure. Moreover, the graphite fragments filled on both sides of the carbon nanotube film structure and the graphite fragments distributed on both sides of the carbon nanotube film structure are combined by carbon-carbon bonds to form a unitary structure. At this time, the carbon nanotube film structure may be completely coated by the graphite structure and composited inside the graphite structure. Therefore, from a macroscopic point of view, the graphite structure is a sponge-like structure, and the carbon nanotube film structure is embedded therein. In other words, the plurality of carbon nanotubes are disposed in the graphite structure in the form of a self-supporting carbon nanotube film structure, and the graphite structure and the plurality of carbon nanotubes pass the van der Waals and carbon-carbon bonds. Combine.

The carbon nanotube composite structure includes a carbon nanotube film structure formed of a plurality of carbon nanotubes and a plurality of graphite fragments filled in the carbon nanotube film structure. In addition to being combined with van der Waals force, the plurality of carbon nanotubes can be tightly bonded by the graphite fragments, thereby increasing the bonding force between the plurality of carbon nanotubes and improving the naphthalene Mechanical properties of the carbon nanotube composite structure. The graphite segment and the carbon nanotube structure have a small density and are both carbon materials. Therefore, the carbon nanotube composite structure formed by combining the plurality of graphite segments and the plurality of carbon nanotubes has a small density. Corrosion resistance, moisture resistance and other advantages.

When the carbon nanotube structure comprises at least one nanocarbon line structure, the polymer can be graphitized into a plurality of graphite fragments and graphitized into a plurality of graphite fibers. Specifically, if graphitization is carried out by rapid heating in the method of graphitization, the polymer will be graphitized into a plurality of graphite fragments. The graphite segment and the nanocarbon pipeline structure are combined by carbon-carbon bonds to form a carbon nanotube composite structure. Whereas in the method of graphitization, graphitization is carried out by slow heating, the polymer will be graphitized into a plurality of graphite fibers. The graphite fibers and the carbon nanotubes are bonded by van der Waals and carbon-carbon bonds. The plurality of graphite fibers in the graphite fiber structure are bonded to each other by a carbon-carbon bond or a van der Waals force, and form a unitary structure.

The plurality of carbon nanotubes in the same nanocarbon pipeline extend substantially along the axial direction of the nanocarbon pipeline, so that the graphite fibers wound or coated with the plurality of carbon nanotubes are also substantially along the nanocarbon pipeline. Axial extension. Specifically, when the plurality of carbon nanotubes in the nanocarbon pipeline are connected end to end by van der Waals force and extend substantially spirally along the axial direction of the nanocarbon pipeline, the graphite fiber is also substantially along the nanocarbon pipeline. The axial direction extends in a spiral shape. When the plurality of carbon nanotubes in the nanocarbon pipeline are connected end to end by van der Waals force The nanocarbon pipelines are arranged in an axially preferred orientation, and the graphite fibers are also arranged substantially in an axially preferred orientation along the nanocarbon pipeline. The graphite fibers in the same nanocarbon pipeline or nanocarbon pipeline structure can be bonded by van der Waals force or by carbon-carbon bonds. Preferably, the graphite fibers in the same nanocarbon pipeline are bonded by carbon-carbon bonds. .

The carbon nanotube composite structure can also be regarded as a composite of two carbon materials of graphite fiber and carbon nanotube. Specifically, the carbon nanotube composite structure may include a plurality of graphite fibers each coated or wound with a plurality of carbon nanotubes connected end to end. The plurality of carbon nanotubes are connected end to end by van der Waals force and extend axially along the graphite fiber. The plurality of graphite fibers may be disposed in parallel, wound or woven with each other. The graphite fiber structure may be formed by combining van der Waals or carbon-carbon bonds between the plurality of graphite fibers.

The carbon nanotube composite structure includes a nanocarbon pipeline structure formed of a plurality of carbon nanotubes and a graphite fiber distributed in the nanocarbon pipeline structure. In addition to being combined with van der Waals force, the plurality of carbon nanotubes can be tightly bonded by the graphite fibers, thereby increasing the bonding force between the plurality of carbon nanotubes and improving the naphthalene The mechanical properties of the carbon nanotube composite structure, in particular, can improve the mechanical properties along the axial direction of the nanocarbon pipeline structure. The graphite fiber and the carbon nanotube structure have a small density and are both carbon materials. Therefore, the carbon nanotube composite structure formed by combining the plurality of graphite fibers and the plurality of carbon nanotubes has a small density. Corrosion resistance, moisture resistance and other advantages.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by those skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

Claims (13)

A method for preparing a carbon nanotube composite structure, comprising the steps of: providing a carbon nanotube structure, the carbon nanotube structure is a self-supporting structure, and the carbon nanotube structure comprises a plurality of carbon nanotubes By polymerizing with a van der Waals force; compounding a polymer in the carbon nanotube structure; and graphitizing the polymer compounded in the carbon nanotube structure to graphitize the polymer into a graphite structure. The method for preparing a carbon nanotube composite structure according to claim 1, wherein the method for compounding the carbon nanotube structure with the polymer specifically comprises the step of: infiltrating the carbon nanotube structure into a polymerization. The solution is complexed with the polymer. The method for preparing a carbon nanotube composite structure according to claim 2, wherein the polymer solution comprises an organic solvent, and the contact angle of the organic solvent to the carbon nanotubes is less than 90 degrees. The method for producing a carbon nanotube composite structure according to claim 3, wherein the organic solvent has a surface tension of 20 mN/m or more. The method for preparing a carbon nanotube composite structure according to claim 1, wherein the method for compounding the carbon nanotube structure with the polymer specifically comprises the step of: infiltrating the carbon nanotube structure into a polymerization. And reacting the polymer monomer, and polymerizing the polymer monomer to form a polymer and recombining with the carbon nanotube structure. The method for preparing a carbon nanotube composite structure according to claim 1, wherein the polymer comprises polyacrylonitrile, polyvinyl alcohol, polypropylene, polystyrene, poly Vinyl chloride or polyethylene terephthalate. The method for preparing a carbon nanotube composite structure according to claim 1, wherein the carbon nanotube structure comprises a carbon nanotube membrane structure, and the carbon nanotube membrane structure has a plurality of micropores. The method for preparing a carbon nanotube composite structure according to claim 7, wherein the carbon nanotube membrane structure comprises a flocculation membrane, a milled membrane or at least two layers of carbon nanotube membranes. The method for preparing a carbon nanotube composite structure according to claim 7, wherein the micropores are formed by connecting a plurality of carbon nanotubes through a van der Waals force, and the pore size is from 1 nm to 1 nm. Between 500 nm. The method for preparing a carbon nanotube composite structure according to claim 7, wherein the graphite structure comprises a plurality of graphite fragments filled in the micropores, and the plurality of graphite fragments are bonded by carbon-carbon bonds, The graphite fragments are combined with the carbon nanotube bonds and van der Waals in the carbon nanotube structure. The method for preparing a carbon nanotube composite structure according to claim 1, wherein the carbon nanotube structure comprises a nano carbon pipeline structure, and the plurality of nanocarbon pipeline structures are arranged in parallel, wound or woven with each other. The method for preparing a carbon nanotube composite structure according to claim 11, wherein the nanocarbon pipeline structure comprises a plurality of carbon nanotubes connected end to end by van der Waals force and extending axially along the nanocarbon pipeline . The method for preparing a carbon nanotube composite structure according to claim 11, wherein the graphite structure comprises a plurality of graphite fibers wound or coated around the plurality of carbon nanotube structures.