TWI415883B - Carbon nanotube composite - Google Patents

Abstract

The present invention relates to a carbon nanotube composite. The carbon nanotube composite includes a substrate having a surface; a carbon nanotube structure disposed in the substrate and adjacent with the surface of the substrate, the carbon nanotube structure includes a plurality of carbon nanotubes joined with each other with van der Waals attractive force, and a distance between the surface and the carbon nanotube structure is in a range from about 0 to about 10 millimeters.

Description

Nano carbon tube composite

The invention relates to a composite material, in particular to a carbon nanotube composite material.

Since the early 1990s, nanomaterials represented by carbon nanotubes have attracted great attention due to their unique structure and properties. In recent years, with the deepening of research on carbon nanotubes and nanomaterials, its broad application prospects are constantly emerging. For example, due to the unique electromagnetic, optical, mechanical, and chemical properties of carbon nanotubes, a large number of applications in field emission electron sources, sensors, new optical materials, soft ferromagnetic materials, etc. Was reported.

A common application of a carbon nanotube is to form a carbon nanotube on the surface of a substrate for use as an electronic device, such as an electron emission source or as a conductive layer and an electrode, or as an electromagnetic mask layer or the like. The method of forming the carbon nanotubes on the surface of the substrate is usually to bond the carbon nanotubes to the surface of the substrate by using a binder. In the carbon nanotube composite material prepared by the method, the carbon nanotubes are exposed on the surface of the carbon nanotube composite material, and during use, the carbon nanotubes are easily detached or destroyed, thereby damaging the nanocarbon. The surface conductivity and service life of the tube composites affect the application in some applications.

In view of this, it is indeed necessary to provide a carbon nanotube composite material, the composite material The surface is electrically conductive while the carbon nanotubes need not be exposed to the surface of the carbon nanotube composite.

A carbon nanotube composite material comprising: a substrate having a surface; a carbon nanotube structure, the carbon nanotube structure being disposed in the substrate and disposed adjacent to a surface of the substrate, The carbon nanotube structure comprises a plurality of carbon nanotubes interconnected by van der Waals, the surface being at a distance from the carbon nanotube structure of greater than 0 to less than or equal to 10 microns.

Compared with the prior art, in the carbon nanotube composite material provided by the invention, the carbon nanotube structure is directly disposed in the matrix material, and the carbon nanotubes need not be exposed to the surface of the carbon nanotube composite material, and the process is not used during use. It will cause damage to the carbon nanotube composite material; the distance from the surface of the substrate to the structure of the carbon nanotube is less than 10 microns, and the surface of the carbon nanotube composite has electrical conductivity and can be applied to various fields.

10‧‧‧Nano Carbon Tube Composites

12‧‧‧ base

122‧‧‧ surface

14‧‧‧Nano Carbon Tube Structure

FIG. 1 is a schematic structural view of a carbon nanotube composite material according to an embodiment of the present invention.

2 is a flow chart of a method for preparing a carbon nanotube composite material according to an embodiment of the present invention.

FIG. 3 is a scanning electron micrograph of a carbon nanotube structure formed on a surface of a substrate according to an embodiment of the present invention.

4 is a combination diagram of a digital photo of a surface of a carbon nanotube composite material and a photograph under an optical microscope according to an embodiment of the present invention.

FIG. 5 is a scanning electron micrograph of a side surface of a carbon nanotube composite material according to an embodiment of the present invention.

FIG. 6 is a comparative photograph of the effect of the carbon nanotube structure on the surface of the substrate after the microwave treatment and microwave treatment are performed on the wettability of the water droplets according to an embodiment of the present invention.

The carbon nanotube composite material of the present invention and a preparation method thereof will be further described in detail below with reference to the accompanying drawings and specific embodiments.

The invention provides a carbon nanotube composite material comprising a matrix and a carbon nanotube structure. The substrate has a surface, and the carbon nanotube structure is disposed in the substrate and disposed adjacent to the surface. The distance from the surface of the substrate to the carbon nanotube structure is greater than 0 and less than or equal to 10 microns. The base material is a polymer material, and a sheet resistance of the surface of the carbon nanotube composite material is less than or equal to 8 kilohms.

Referring to FIG. 1, a carbon nanotube composite material 10 according to an embodiment of the present invention. The carbon nanotube composite 10 includes a substrate 12 and a carbon nanotube structure 14. The substrate 12 has a surface 122 that is disposed within the substrate 12 and disposed adjacent the surface 122.

The material of the substrate 12 may be a polymer material. The polymer material includes epoxy resin, bismaleimide resin, cyanate resin, polypropylene, polyethylene, polystyrene, polyvinyl alcohol, polyphenylene alcohol, polycarbonate or polymethacrylic acid. Methyl ester, etc. Preferably, the base 12 has a melting point of less than 600 °C.

The carbon nanotube structure 14 includes a plurality of uniformly distributed carbon nanotubes, and the carbon nanotubes are tightly coupled by van der Waals. The carbon nanotube structure 14 can also be a pure structure composed of carbon nanotubes. There is a gap between the carbon nanotubes in the carbon nanotube structure 14 such that the carbon nanotube structure 14 includes a plurality of micro-gap. The carbon nanotubes in the carbon nanotube structure 14 are disordered or ordered. The disordered arrangement here means that the arrangement direction of the carbon nanotubes is irregular, and the ordered arrangement here means that at least most of the arrangement of the carbon nanotubes has a certain regularity. Specifically, when the carbon nanotube structure 14 includes a disordered arrangement of carbon nanotubes, the carbon nanotubes are intertwined or isotropically aligned; when the carbon nanotube structure 14 includes an ordered arrangement of carbon nanotubes The carbon nanotubes are arranged in a preferred orientation in one direction or in a plurality of directions. The thickness of the carbon nanotube structure 14 is preferably from 0.5 nm to 10 μm. The carbon nanotube structure 14 has a heat capacity per unit area of less than 2 x 10 ^-4 joules per square centimeter Kelvin. Preferably, the carbon nanotube structure 14 has a heat capacity per unit area of less than or equal to 1.7 x 10 ^-6 joules per square centimeter Kelvin. The carbon nanotube structure 14 may comprise a carbon nanotube membrane, or a plurality of parallel and gaplessly laid or/and laminated carbon nanotube membranes. The carbon nanotube structure 14 can include a plurality of nanocarbon line-like structures arranged in parallel, intersected, or woven in a manner. The carbon nanotubes in the carbon nanotube structure 14 include one or more of a single-walled carbon nanotube, a double-walled carbon nanotube, and a multi-walled carbon nanotube. The single-walled carbon nanotube has a diameter of 0.5 nm to 50 nm, the double-walled carbon nanotube has a diameter of 1.0 nm to 50 nm, and the multi-walled carbon nanotube has a diameter of 1.5. Nano ~ 50 nm.

In the carbon nanotube composite 10, the substrate 12 is filled into the micro-gap in the carbon nanotube structure 14, and the substrate 12 is tightly bonded to the carbon nanotubes in the carbon nanotube structure 14. The substrate 12 encases the entire carbon nanotube structure 14. The carbon nanotube structure 14 maintains a layered structure in the substrate 12. The vertical distance from the surface 122 of the substrate 12 to the carbon nanotube structure 14 is greater than zero and less than or equal to 10 microns. Preferably, the distance from the surface 122 of the substrate 12 to the carbon nanotube structure 14 is less than 100 nanometers. The distance from the surface 122 of the substrate 12 to the carbon nanotube structure 14 When the distance is less than or equal to 10 micrometers, the surface 122 of the carbon nanotube composite has electrical conductivity and a sheet resistance of 8 kilohms or less. In this embodiment, the surface resistance of the substrate is preferably 5 kilohms or less. The thickness of the base material on the surface of each of the carbon nanotubes is greater than 0 and less than or equal to 10 microns. Preferably, the thickness of the base material on the surface of each of the carbon nanotubes is from 20 nm to 30 nm.

The carbon nanotube composite of the present invention will be further described below by introducing the preparation method of the above carbon nanotube composite. Referring to FIG. 2, the present invention further provides a method for preparing a carbon nanotube composite material according to the above embodiment. The preparation method of the carbon nanotube composite material comprises the following steps:

Step 1. Providing a substrate having a surface.

The surface may be a flat surface or a curved surface. In this embodiment, the base body has a rectangular parallelepiped structure with a thickness of 3 mm and a side length of 50 mm. The surface is a square plane with a side length of 50 mm. The material of the substrate is polyethylene.

Step 2, providing a carbon nanotube structure, the carbon nanotube structure is disposed on a surface of the substrate, the carbon nanotube structure comprises a plurality of carbon nanotubes, and the plurality of carbon nanotubes are formed There are multiple micro gaps.

The method for disposing the carbon nanotube structure on the surface of the substrate may be formed by spraying or coating a slurry containing a carbon nanotube on the surface of the sheet structure, and then volatilizing the solvent, or directly disposing the carbon The tube structure is laid on the surface. In this embodiment, preferably, the carbon nanotube structure is a self-supporting structure. The self-supporting carbon nanotube film does not require a large-area carrier support, and as long as the supporting force is provided on both sides, the whole film can be suspended and maintained in a self-membranous state, that is, the carbon nanotube film is placed (or fixed). When the two supports are disposed at a fixed distance, the carbon nanotube film located between the two supports can maintain its own lamellar state. The micro-gap in the carbon nanotube structure has a maximum pore diameter of 10 μm or less. The self-supporting carbon nanotube structure can be formed on the surface by laying. When a self-supporting carbon nanotube structure is used, it is not necessary to form a slurry of the carbon nanotubes, and it is not necessary to solve the problem of dispersion of the carbon nanotubes, and no other impurities are introduced in the carbon nanotube structure. Moreover, the self-supporting carbon nanotube structure can be used to form the carbon nanotube structure on the surface of the substrate by laying, and the operation is simple.

The carbon nanotube structure may include a carbon nanotube membrane, or a plurality of carbon nanotube membranes laid in parallel or without gaps. The carbon nanotube film is a carbon nanotube film, a carbon nanotube film or a carbon nanotube film.

(1) A method for preparing a carbon nanotube film comprises the steps of: firstly, providing a carbon nanotube array formed on a growth substrate, the array being a super-aligned carbon nanotube array.

The method for preparing the carbon nanotube array adopts a chemical vapor deposition method, and the specific steps thereof include: (a) providing a flat growth substrate, the growth substrate may be a P-type or N-type germanium growth substrate, or an oxide layer may be formed. The ruthenium growth substrate, the embodiment of the present invention preferably uses a 4 inch ruthenium growth substrate; (b) uniformly forms a catalyst layer on the surface of the growth substrate, and the catalyst layer material may be selected from iron (Fe), cobalt (Co), nickel ( Ni) or one of any alloy of any combination thereof; (c) annealing the growth substrate on which the catalyst layer is formed in air at 700 ° C to 900 ° C for about 30 minutes to 90 minutes; (d) The treated growth substrate is placed in a reaction furnace, heated to 500 ° C to 740 ° C in a protective gas atmosphere, and then reacted with a carbon source gas for about 5 minutes to 30 minutes to grow to obtain a carbon nanotube array. The carbon nanotube array is a plurality of pure carbon nanotube arrays formed of carbon nanotubes that are parallel to each other and perpendicular to the growth substrate. The aligned carbon nanotube array contains substantially no impurities, such as amorphous carbon or residual catalyst metal particles, etc., by controlling the growth conditions described above.

Secondly, a drawing tool is used to pull the carbon nanotubes from the carbon nanotube array to obtain at least one carbon nanotube film, which specifically comprises the following steps: (a) from the super-sequential carbon nanotube array Selecting one or a plurality of carbon nanotubes having a certain width, preferably adopting a tape, a braid or a clip having a certain width to contact the array of carbon nanotubes to select one or a plurality of carbon nanotubes having a certain width; (b The selected carbon nanotubes are drawn at a certain speed to form a plurality of carbon nanotube fragments connected end to end, thereby forming a continuous carbon nanotube film. The pull direction is substantially perpendicular to the growth direction of the nanotube array.

In the above stretching process, the plurality of carbon nanotube segments are gradually separated from the growth substrate in the stretching direction under the tensile force, and the selected plurality of carbon nanotube segments are respectively combined with the other due to the effect of the van der Waals force. The carbon nanotube segments are continuously pulled out end to end to form a continuous, uniform, and wide-width carbon nanotube film.

The width of the carbon nanotube film is related to the size of the carbon nanotube array. The length of the carbon nanotube film is not limited and can be obtained according to actual needs. When the area of the carbon nanotube array is 4 inches, the width of the carbon nanotube film is 0.5 nm to 10 cm, and the thickness of the carbon nanotube film is 0.5 nm to 10 μm.

The carbon nanotube film can be used as a carbon nanotube structure, or at least two layers of carbon nanotube film can be stacked or arranged side by side to form a carbon nanotube structure.

(2) The preparation method of the carbon nanotube flocculation membrane comprises the following steps: First, a carbon nanotube raw material is provided.

The carbon nanotube raw material may be a carbon nanotube prepared by various methods such as chemical vapor deposition, graphite electrode constant current arc discharge deposition or laser evaporation deposition.

The aligned carbon nanotube arrays are scraped off the substrate using a blade or other tool to obtain a carbon nanotube material. Preferably, in the carbon nanotube raw material, the length of the carbon nanotube is greater than 100 micrometers.

Next, the above carbon nanotube raw material is added to a solvent and subjected to flocculation treatment to obtain a nano carbon tube floc structure, and the above carbon nanotube floc structure is separated from the solvent, and the carbon nanotube is separated. The flocculated structure is shaped to obtain a carbon nanotube flocculation film.

The solvent can be selected from water, a volatile organic solvent, and the like. The flocculation treatment can be carried out by a method such as ultrasonic dispersion treatment or high-intensity stirring. Preferably, the embodiment of the invention uses ultrasonic dispersion for 10 minutes to 30 minutes. Due to the extremely large specific surface area of the carbon nanotubes, there is a large van der Waals force between the intertwined carbon nanotubes. The above flocculation treatment does not completely disperse the carbon nanotubes in the carbon nanotube raw material in the solvent, and the carbon nanotubes are mutually attracted and entangled by the van der Waals force to form a network structure.

The method for separating the carbon nanotube floc structure specifically comprises the steps of: pouring the solvent containing the carbon nanotube floc structure into a funnel with a filter paper; and drying for a period of time to obtain a separation. Nano carbon tube floc structure.

The shaping treatment process of the nano carbon tube floc structure specifically comprises the steps of: placing the above carbon nanotube floc structure in a container; spreading the nano carbon tube floc structure according to a predetermined shape; applying A certain pressure is applied to the expanded carbon nanotube floc structure; and the residual solvent in the nano carbon tube floc structure is dried or the solvent is naturally volatilized to obtain a carbon nanotube flocculation film.

It will be appreciated that the present invention controls the thickness and areal density of the carbon nanotube flocculation membrane by controlling the area over which the carbon nanotube floc is spread. The larger the area spread by the carbon nanotube floc structure, the smaller the thickness and areal density of the carbon nanotube flocculation film.

In addition, the step of separating and shaping the carbon nanotube floc structure can also be directly carried out by suction filtration, and specifically includes the following steps: providing a pore filter membrane and an air suction funnel; and the above-mentioned carbon nanotube containing The solvent of the structure is poured into the suction funnel through the pore filter membrane; after suction filtration and drying, a carbon nanotube flocculation membrane is obtained. The pore filter membrane is a filter membrane having a smooth surface and a size of 0.22 μm. Since the suction filtration method itself will provide a large gas pressure on the carbon nanotube floc structure, the carbon nanotube floc structure directly forms a uniform carbon nanotube flocculation membrane by suction filtration. Moreover, since the pore filter membrane surface is smooth, the carbon nanotube flocculation membrane is easily peeled off, and a self-supporting carbon nanotube flocculation membrane is obtained.

It can be understood that the carbon nanotube flocculation membrane has a certain thickness, and the thickness of the carbon nanotube flocculation membrane can be controlled by controlling the area spread by the carbon nanotube floc structure and the pressure. The carbon nanotube flocculation membrane can be used as a carbon nanotube structure, or at least two layers of carbon nanotube flocculation membranes can be stacked or arranged side by side to form a carbon nanotube structure.

(C) The preparation method of the carbon nanotube rolled film comprises the following steps: First, an array of carbon nanotubes is provided on a growth substrate, and the array is an array of aligned carbon nanotubes.

The carbon nanotube array is preferably a super-aligned array of carbon nanotubes. The carbon nanotube array is prepared in the same manner as the above-described carbon nanotube array.

Next, a carbon nanotube array is extruded by using a pressing device to obtain a carbon nanotube rolled film, wherein the pressing device applies a certain pressure to the carbon nanotube array. During the pressing process, the carbon nanotube array is separated from the growth substrate by pressure to form a carbon nanotube rolled film having a self-supporting structure composed of a plurality of carbon nanotubes, and The plurality of carbon nanotubes are substantially parallel to the surface of the carbon nanotube rolled film.

The pressing device is an indenter, the surface of the indenter is smooth, and the shape and extrusion direction of the indenter determine the arrangement of the carbon nanotubes in the prepared carbon nanotube rolled film. Preferably, when the planar indenter is pressed in a direction perpendicular to the growth substrate of the carbon nanotube array, the carbon nanotubes are obtained as isotropically arranged carbon nanotubes; when the roller is used When the indenter is rolled in a certain fixed direction, a carbon nanotube film which is aligned along the fixed direction of the carbon nanotubes can be obtained; when the roller-shaped indenter is rolled in different directions, the nanometer can be obtained. A carbon nanotube rolled film in which carbon tubes are aligned in different directions.

It can be understood that when the above-mentioned carbon nanotube array is extruded by the above different methods, the carbon nanotubes are poured under the action of pressure, and are attracted and connected with the adjacent carbon nanotubes through the van der Waals force. A carbon nanotube laminated film having a self-supporting structure composed of a plurality of carbon nanotubes.

It can be understood that the carbon nanotube rolled film has a certain thickness, and the thickness can be controlled by the height of the carbon nanotube array and the pressure. Therefore, the carbon nanotube rolled film can be directly used as a carbon nanotube structure. In addition, at least two layers of carbon nanotube rolled films may be stacked or arranged side by side to form a carbon nanotube structure.

Alternatively, the carbon nanotube structure may be further dried with an organic solvent and then dried. The organic solvent may be ethanol, methanol, chloroform or propanol or the like. Preferably, the organic solvent is a volatile organic solvent. The carbon nanotube structure can be directly immersed in a container containing an organic solvent. After the carbon nanotube structure can also be laid on a substrate, the organic solvent is dropped onto the surface of the carbon nanotube structure to infiltrate the carbon nanotube structure. It can be understood that the carbon nanotube structure can be formed on the surface of the substrate, and the organic solvent is dropped on the surface of the carbon nanotube structure until the carbon nanotube structure is completely wetted by the organic solvent, and then dried. In this embodiment, after the carbon nanotube structure is formed on the substrate, the carbon nanotube structure is infiltrated with ethanol.

In this embodiment, the carbon nanotube structure comprises a layer of carbon nanotube film, and the carbon nanotube structure has a thickness of nanometer. Figure 3 is a scanning electron micrograph of the carbon nanotube structure formed on the surface of the substrate in the present embodiment. As can be seen from Figure 3, the carbon nanotube structure is located above the surface.

Step 3: placing the carbon nanotube structure and the substrate in an electromagnetic wave environment, so that the surface of the substrate melts and penetrates into a plurality of micro gaps of the carbon nanotube structure.

The electromagnetic wave has a power of 300 watts to 2000 watts and a frequency of 1 GHz to 10 GHz. The electromagnetic wave may be radio waves, microwaves, infrared rays or far infrared rays. In this embodiment, the electromagnetic wave is a microwave, and the power of the microwave is 300 watts to 1500 watts, and the frequency is From 1 GHz to 5 GHz, the carbon nanotube structure and the substrate are placed in a microwave environment for a period of from 1 second to 300 seconds, preferably from 3 seconds to 90 seconds. When the matrix material is the same, the greater the power of the microwave, the shorter the placement time of the carbon nanotube structure and the matrix in the microwave environment. The base material is a polymer material, and the polymer material generally has good wettability with the carbon nanotubes, and can easily penetrate into the voids of the carbon nanotube structure after being melted on the surface of the substrate. Since the matrix is a polymer material, the absorption of microwave energy is much smaller than that of the carbon nanotube structure, and the heat capacity of the matrix is larger than that of the nanocarbon tube layer. Therefore, the temperature rise of the matrix itself by the microwave energy absorbed by itself The height is negligible, that is, it does not melt the entire substrate. Since the heat capacity of the carbon nanotube structure is small and the interaction with the microwave is strong, the structure of the carbon nanotubes after absorbing the microwave energy rapidly raises the temperature, thereby making the matrix in contact with the carbon nanotube structure. The surface temperature rises. When the surface of the substrate reaches a certain temperature, melting begins. When the surface is melted, the contact between the outer wall of the carbon nanotube and the substrate in the carbon nanotube structure is more sufficient, so that the thermal resistance of the interface between the carbon nanotube structure and the surface of the substrate is significantly reduced, which facilitates greater heat flow. Matrix. While the carbon nanotube structure interacts with the microwave and rapidly heats up, the high specific surface area carbon nanotubes can effectively transfer heat to the matrix with greater heat capacity. Therefore, during the microwave heating process, the rising temperature of the carbon nanotube structure can be effectively controlled below 700 ° C to avoid oxidation combustion of the carbon nanotube structure in the air. During the melting of the matrix, the matrix expands and absorbs heat. During the heat absorption and expansion of the matrix, the molten matrix will penetrate into the micro-gap of the carbon nanotube structure. It can be understood that the sinking depth of the carbon nanotube structure in a suitable range in the matrix is achieved by controlling the microwave intensity as well as the heating temperature and time, such as the sinking of the carbon nanotube structure into the surface of the substrate to be completely buried or nanocarbon. The tube structure sinks into the surface of the substrate until it is flush with the surface of the substrate, that is, the carbon nanotubes on the surface of the carbon nanotube structure are just from the substrate. The surface is exposed. During this process, due to the presence of micro-gap in the carbon nanotube structure, the molten matrix material will be filled in the micro-gap and coated on the surface of the carbon nanotube. When the micro-gap is filled, the nano-particles are filled. The sinking power of the carbon tube structure in the base material is slowed down, and the thickness of the base material covering the upper surface of the carbon nanotube structure can be controlled within 100 nm. After the matrix penetrates into the micro-gap of the carbon nanotube structure, the matrix can completely encapsulate the carbon nanotubes in the carbon nanotube structure. That is, the carbon nanotube structure is buried under the surface.

In this embodiment, the material of the substrate is polyethylene, and the melting point of the polyethylene is about 137 ° C. Therefore, when the temperature of the carbon nanotube structure reaches 137 ° C or slightly higher than the melting point of the polyethylene, the surface 122 of the substrate begins to melt. After standing for 10 seconds in a microwave environment, the substrate completely encapsulates the carbon nanotube structure.

It will be understood that the above steps can also be carried out in a vacuum environment or in the presence of a protective gas. The vacuum environment may have a vacuum of 10 ^-2 to 10 ^-6 Pa. The shielding gas includes nitrogen and an inert gas. In the presence of a vacuum environment or a protective gas, the carbon nanotube structure can be protected from being destroyed at a high temperature, and the temperature of the carbon nanotube structure can reach about 2000 °C.

Referring to FIG. 1 and FIG. 4 together, in this embodiment, after the carbon nanotube structure 14 and the substrate 12 are placed in a microwave environment for 10 seconds, the surface scan of the obtained obtained carbon nanotube composite material 10 is taken out. Electron micrograph. Referring to FIG. 3, after the carbon nanotube structure 14 and the substrate 12 are placed in a microwave environment for 10 seconds, the carbon nanotube structure 14 is buried under the surface 122 by the substrate 12, and the surface of the carbon nanotube composite 10 is relatively smooth. And flat. It can be seen from the side view of the scanning electron micrograph of the carbon nanotube composite material 10 of Fig. 5 that the carbon nanotubes in the carbon nanotube structure 14 are covered by the matrix material. Compare Figure 5 The diameter of the single carbon nanotube in the carbon nanotube composite material 10 is covered by the matrix material and the diameter of the carbon nanotube in the original carbon nanotube structure 14 is found to be 10 - the diameter of the carbon nanotube is originally 10- At 30 nm, the diameter of the structure formed by coating with the base material is increased to 70-90 nm. Therefore, it can be known that the distance from the surface of the substrate to the structure of the carbon nanotube can be considered as the difference between the radius of the original carbon nanotube and the radius after being coated, that is, about 30 nm.

Referring to FIG. 6, in the present embodiment, after the carbon nanotube structure 14 is laid on the surface 122 of the substrate 12, the difference in microstructure after the microwave treatment and the microwave treatment causes a difference in the water droplet wetting angle. In Fig. 6A, a single-layered carbon nanotube film is provided on the surface of the substrate 12 without microwave treatment. A drop of 5 μL of water was dropped on the surface of the carbon nanotube film, and the water droplets were extended in the direction in which the carbon nanotubes were stretched in the carbon nanotube film to form an elliptical shape having a cross-sectional area of 5.69 mm ² . Referring to FIG. 6B, after the microwave treatment is performed to form the carbon nanotube composite material, an equal amount of water droplets can be kept in a circular shape after the surface of the carbon nanotube composite material of the present invention, and the cross-sectional area is 5.14 mm ² on the substrate. The contact angle is isotropic. This phenomenon indicates that the carbon nanotube film has been covered by a layer of nanometer-thick smooth matrix material, the gap in the carbon nanotube film is filled by the matrix material, and the nanometer in the carbon nanotube film is pulled. The carbon tube is covered by the base material, thereby ensuring that the conductivity of the surface of the carbon nanotube composite material is not affected by the humid environment, and functions to protect the conductive layer of the carbon nanotube.

The surface of the carbon nanotube composite material 10 has electrical conductivity. In this embodiment, after the single-layer carbon nanotube film is formed into the carbon nanotube composite material, the conductive properties of the surface of the carbon nanotube composite material have respective To the same sex, the sheet resistance was tested in all directions on the surface of the carbon nanotube composite material 10, and the sheet resistance was about 5 kΩ. Moreover, the surface 122 of the substrate 12 of the carbon nanotube composite 10 has better scratch resistance. The carbon nanotube composite material 10 obtained in the present embodiment was prepared into a volume of 8×8 mm ² square, and a set of copper electrodes were adhered to the ends of the edges with a conductive adhesive to measure the surface of the carbon nanotube composite material 10. resistance. A tip area of about 0.25 mm ² is applied to the surface 122 of the carbon nanotube composite 10 at a constant velocity perpendicular to the surface 122. The tip is wrapped by an alcohol-impregnated batt and applies a force of 0.7 Newtons to the tip. Surface 122. After scraping 50 times along the same line, the sheet resistance of the surface 122 of the carbon nanotube composite 10 varies little, less than 10%. Such a wear-resistant surface that fully utilizes CNT conductivity can meet the needs of various antistatic devices. If the carbon nanotube structure 14 is directly laid on the surface of the substrate, the carbon nanotube structure 14 at the friction portion is completely peeled off after the tip of the needle is not subjected to microwave treatment, and the carbon nanotube composite material is completely removed. The surface loses overall conductivity.

The carbon nanotube composite material provided by the invention and the preparation method thereof have the following advantages: First, the surface of the invention is formed by the surface of the carbon nanotube structure and the electromagnetic wave heating substrate contacting the carbon nanotube structure, thereby forming a surface conductive The carbon nanotube composite material does not need to heat the entire substrate, does not cause damage to the substrate itself, and is beneficial to save energy. Second, the method provided by the invention is simple and controllable and is suitable for industrial applications. Third, the surface of the carbon nanotube composite material provided by the invention has good electrical conductivity and good performance. Fourth, the surface of the carbon nanotube composite material has strong scratch resistance, so that the carbon nanotube composite material has a long service life and a wide application range. Fifthly, the carbon nanotube composite material provided by the invention can be used as a transparent conductive substrate of a touch screen, and since the binder is not required, the carbon nanotube composite material has a small interface and can have good light transmittance.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. please. 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 persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

10‧‧‧Nano Carbon Tube Composites

12‧‧‧ base

122‧‧‧ surface

14‧‧‧Nano Carbon Tube Structure

Claims (15)

A carbon nanotube composite material comprising: a substrate having a surface; wherein the carbon nanotube composite further comprises a carbon nanotube structure, wherein the carbon nanotube structure is disposed on The carbon nanotube structure comprises a plurality of carbon nanotubes connected to each other by van der Waals force, and the distance from the surface to the carbon nanotube structure is greater than 0 and less than or equal to 10 micrometers. The carbon nanotube composite material according to Item 1, wherein the base material is a polymer material. The carbon nanotube composite material according to Item 2, wherein the polymer material is epoxy resin, bismaleimide resin, cyanate resin, polypropylene, polyethylene, polystyrene , polyvinyl alcohol, polyphenylene alcohol, polycarbonate or polymethyl methacrylate. The carbon nanotube composite material according to Item 1, wherein the base material has a melting point of less than 600 °C. The carbon nanotube composite material according to Item 1, wherein the carbon nanotube is coated with a base material, and the base material of each surface of the carbon nanotube has a thickness of 10 μm or less. The carbon nanotube composite material according to Item 5, wherein the base material of each surface of the carbon nanotubes has a thickness of 20 nm to 30 nm. The carbon nanotube composite material according to claim 1, wherein the surface of the carbon nanotube composite material is a smooth surface. The carbon nanotube composite material according to Item 1, wherein the carbon nanotube structure is a pure structure composed of a carbon nanotube. The carbon nanotube composite material according to claim 1, wherein a gap exists between the carbon nanotubes in the carbon nanotube structure, and the matrix material is filled in a gap in the carbon nanotube structure. The carbon nanotube composite material according to Item 1, wherein the carbon nanotubes in the carbon nanotube structure are intertwined, and the carbon nanotube structure is isotropically arranged. The carbon nanotube composite material according to claim 1, wherein the carbon nanotubes in the carbon nanotube structure are arranged end to end in a preferred orientation in the same direction. The carbon nanotube composite material according to Item 1, wherein the surface resistance of the surface of the substrate is less than or equal to 8 kilohms. A carbon nanotube composite material comprising a substrate and a carbon nanotube structure disposed in the matrix, wherein the carbon nanotube structure maintains a layered structure in the substrate and is disposed adjacent to a surface of the substrate. The base material is a polymer material, and the sheet resistance of the surface of the substrate is less than or equal to 8 kilohms. The carbon nanotube composite of claim 13, wherein the distance from the surface of the substrate to the carbon nanotube structure is greater than 0 and less than or equal to 10 microns. The carbon nanotube composite according to Item 13, wherein the distance from the surface of the substrate to the structure of the carbon nanotube is greater than 0 and less than or equal to 100 nm.