CN103088648B - Preparation method for carbon fiber material with composite nano structure - Google Patents

Abstract

The invention relates to a method for preparing a composite nanostructure carbon fiber material. In the method, carbon fiber cloth is pretreated, and a layer of iron thin film catalyst is attached to the carbon fiber cloth by a liquid phase method or a physical deposition method. In a chemical gas phase reaction chamber, use Argon or nitrogen is used as carrier gas, ethylene or acetylene gas is used as carbon source gas, hydrogen is used as reducing gas, carbon nanotubes are grown in situ on carbon fiber cloth, and then gas containing titanium organic matter is brought into chemical vapor deposition through carrier gas In the reaction chamber, titanium dioxide is grown on the periphery of the carbon nanotubes to form a titanium dioxide nanoshell coated on the carbon nanotubes, and a composite nanostructure carbon fiber material can be obtained. The material obtained by the method of the present invention has high mechanical strength, high thermal stability, good chemical inertness and high adsorption performance, supernormal strength of carbon nanotubes, huge aspect ratio, high thermal conductivity, good catalytic activity, chemical High stability, non-toxic, super hydrophilic. The composite nanostructured carbon fiber material will gain important applications in photocatalysis, electrocatalysis and the like.

Description

A kind of preparation method of composite nanostructure carbon fiber material

technical field

The invention belongs to the technical field of nanometer materials, and in particular relates to a preparation method of a composite nanostructure carbon fiber material.

Background technique

Carbon fiber is a microcrystalline graphite material obtained by carbonizing and graphitizing organic fibers. Carbon fiber has excellent mechanical properties, its specific gravity is less than 1/4 of steel, the tensile strength of carbon fiber resin composite is 7-9 times that of steel, and the tensile modulus of elasticity is also higher than that of steel. Carbon fiber also has unique chemical properties. It is an inorganic polymer fiber with a carbon content higher than 90%. It has good fatigue resistance, specific heat and electrical conductivity between non-metal and metal, small thermal expansion coefficient, and corrosion resistance. Well, the density of the fiber is low, the X-ray permeability is good, and the chemical stability is strong. Therefore, carbon fiber materials have been widely used as protective materials, anti-radiation materials, aerospace materials and electrode materials.

As a one-dimensional nanomaterial, carbon nanotubes are light in weight and have many unusual mechanical, thermal, electrical and chemical properties. Carbon nanotubes are also used to make many composite materials with excellent performance because of their large specific surface area and the defect sites on the surface with many active groups.

Titanium dioxide nanomaterials are currently the best photocatalytic materials with high catalytic activity and high stability. At the same time, titanium dioxide nanomaterials also show great application prospects in fuel cells and photochemical water splitting, providing technical possibilities for future green energy solutions.

However, the current method of carbon fiber materials and carbon nanocomposites is completed in two steps, that is, first grow carbon nanotubes, and then disperse the carbon nanotubes into the solution to obtain a carbon nanotube dispersion, and use the dispersed carbon nanotubes The dispersion is then compounded with carbon fibers. The disadvantages of this method of preparing carbon fiber/carbon nanotube composite materials are: (1) the dispersion of carbon nanotubes is not ideal, and it is difficult to form monodisperse, so the excellent properties of carbon nanotubes themselves cannot be reflected after compounding; (2) carbon nanotubes Nanotubes are first grown and then recombined, not grown on carbon fibers in situ, so the combination of the two is relatively weak, so the composited carbon nanotubes are easy to separate from the carbon fibers.

In order to overcome the shortcomings of the existing two-step method for preparing carbon fiber/carbon nanotube composite materials, the invention provides a method for preparing composite nanostructure carbon fiber materials by in-situ growth.

Contents of the invention

The object of the present invention is to provide a method for preparing a composite nanostructured carbon fiber material. The method is realized by growing carbon nanotubes and nano-titanium dioxide in situ on carbon fiber cloth. Attach a layer of iron thin film catalyst on the carbon fiber cloth by method or physical deposition method, put the carbon fiber cloth loaded with the catalyst into the chemical gas phase reaction chamber, use argon or nitrogen as the carrier gas, use ethylene or acetylene gas as the carbon source gas, and hydrogen As a reducing gas, carbon nanotubes are grown in situ on the carbon fiber cloth, and then the gas containing titanium organic matter is brought into the chemical vapor deposition reaction chamber through the carrier gas, and titanium dioxide is grown on the periphery of the carbon nanotubes to form a coating on the carbon nanotubes. Titanium dioxide nano-shells are obtained to obtain composite nanostructure carbon fiber materials. The materials obtained by the method of the present invention possess high mechanical strength, high thermal stability, good chemical inertia and high adsorption performance of carbon fibers, and possess the extraordinary strength of carbon nanotubes at the same time , huge aspect ratio, high thermal conductivity, good catalytic activity, and possesses high chemical stability, non-toxicity, super-hydrophilicity and excellent photocatalytic performance of nano titanium dioxide. Therefore, this composite nanostructured carbon fiber material will gain important applications in photocatalysis and electrocatalysis.

A kind of preparation method of composite nanostructure carbon fiber material of the present invention, carry out according to the following steps:

a. Pretreatment of carbon fiber cloth: put the carbon fiber cloth into a sodium carbonate solution with a concentration of 20-40g/L at a temperature of 60°C, ultrasonically assisted cleaning for 30 minutes, and then clean with deionized water, then place the carbon fiber cloth into acetone solution, ultrasonically assisted cleaning for 20 minutes, and then heat-treat the carbon fiber cloth at 400°C for 30 minutes in an air atmosphere;

b. Through the liquid phase method, put the pretreated carbon fiber cloth into the FeCl ₃ solution with a concentration of 0.05-1.00mol/L and impregnate it to obtain a layer of Fe catalyst attached to the carbon fiber cloth, and then pass clean air into the vapor deposition chamber , heat-treating the Fe catalyst attached to the carbon fiber cloth at a temperature of 450°C for 15 minutes, then raising the temperature to 650-700°C, and passing in hydrogen with a flow rate of 30-100 sccm for 2-8 minutes;

Or through the physical vapor deposition method, using Fe with a purity of 99.99% as the target material, the carbon fiber cloth is deposited by magnetron sputtering or thermal evaporation, and the thickness of the Fe film attached to the carbon fiber cloth is 0.5-8nm. The carbon fiber cloth of the Fe catalyst is directly sent into the chemical vapor deposition chamber, and the temperature is raised to 600-700°C at a heating rate of 50°C/min, and then hydrogen gas with a flow rate of 10-80sccm is introduced for reduction for 2-8 minutes;

c. The carbon fiber cloth obtained by liquid phase method or physical vapor deposition method in step b is subjected to chemical vapor phase method, using argon or nitrogen as carrier gas, ethylene or acetylene gas as carbon source gas, hydrogen as reducing gas, and reacting The temperature is 600-700°C, and the time is 1-30 minutes to grow carbon nanotubes in situ on the carbon fiber cloth;

d. Through the chemical vapor phase method, first use argon or nitrogen as the carrier gas to flush the vapor deposition reaction chamber, the gas flow rate is 300-600sccm, and the flushing time is 5-8 minutes, then use argon or nitrogen as the carrier gas, use Tetraisopropoxytitanium vapor is used as titanium source gas, the reaction temperature is 300-720° C., and the time is 5-30 minutes. Titanium dioxide nanoshells are grown on the outside of carbon nanotubes to obtain composite nanostructure carbon fiber materials.

In step c, the flow rate of argon or nitrogen as carrier gas is 50-500 sccm, the flow rate of ethylene or acetylene gas as carbon source gas is 20-200 sccm, and the flow rate of hydrogen as reducing gas is 5-50 sccm.

In step d, the flow rate of argon or nitrogen as carrier gas is 50-300 sccm, and the flow rate of titanium tetraisopropoxide vapor as titanium source gas is 10-250 sccm.

The method for preparing a composite nanostructured carbon fiber material according to the present invention has the advantage that carbon nanotubes and nano-titanium dioxide are composited through in-situ growth, and are not connected by physical adsorption. Carbon nanotubes The large shared surface with the carbon fiber, the combination is tight, and the titanium dioxide nanoshell grown outside the carbon nanotube, the titanium dioxide in it is more than 95% from the perspective of the structure, and only a few are amorphous and polycrystalline Titanium dioxide, in single crystal titanium dioxide, the proportion of titanium dioxide with anatase structure is greater than 90%, so the advantages of the respective materials are retained to the greatest extent, so that the final composite nanostructured carbon fiber material has the best performance.

Detailed ways

The method for preparing composite nanostructured carbon fiber materials of the present invention will be further described in detail below in conjunction with specific embodiments, but the present invention is not limited to the given examples.

Example 1

a. Pretreatment of carbon fiber cloth: put 100×100mm biaxial carbon fiber cloth into a sodium carbonate solution with a concentration of 30g/L, heat it through an electric furnace until the solution temperature is 60°C, and ultrasonically assist cleaning for 30 minutes. Wash it twice with deionized water, then put the carbon fiber cloth into the acetone solution, and ultrasonically assist cleaning for 20 minutes, then put the carbon fiber cloth into the tube furnace with openings at both ends in the air atmosphere, heat treatment at 400°C for 30 minute;

b. By the liquid phase method, the pretreated carbon fiber cloth is immersed in a _FeCl solution with a concentration of 0.4 mol/L to obtain a layer of Fe catalyst attached to the carbon fiber cloth, and then clean air is introduced into the chemical vapor deposition chamber. Heat-treat the Fe catalyst attached to the carbon fiber cloth at a temperature of 450°C for 15 minutes, then raise the temperature to 650°C, and pass in hydrogen with a flow rate of 60 sccm for 5 minutes;

c. The carbon fiber cloth obtained by the liquid phase method in step b is passed through the chemical vapor phase method, and the flow rate of argon is 100 sccm as carrier gas, the flow rate of acetylene is 50 sccm gas as carbon source gas, and the flow rate of hydrogen is 25 sccm for reduction gas, the reaction temperature is 600°C, and the time is 12 minutes to grow carbon nanotubes in situ on the carbon fiber cloth;

d. Through the chemical vapor phase method, first use argon as a carrier gas to flush the vapor deposition reaction chamber. The gas flow rate is 600 sccm, and the flushing time is 5 minutes. The purpose is to eliminate other gases in the reaction chamber and provide a clean environment for growing nano-titanium dioxide. , and then use the flow rate of argon as 120 sccm as carrier gas, the flow rate of titanium tetraisopropoxide vapor as 18 sccm as titanium source gas, the reaction temperature is 480 ℃, the time is 16 minutes, grow titanium dioxide nano shell outside the carbon nanotube , the composite nanostructure carbon fiber material can be obtained, wherein the average length of the carbon nanotubes is 750 μm, and the average thickness of the nano-titanium dioxide shell around the carbon nanotubes is 8 nm, which is a single crystal anatase structure.

Example 2

a. Pretreatment of carbon fiber cloth: put a 120×120mm triaxial carbon fiber cloth into a sodium carbonate solution with a concentration of 20g/L, heat it through an electric furnace until the solution temperature is 60°C, and ultrasonically assist cleaning for 30 minutes. Wash it twice with deionized water; then put the carbon fiber cloth into the acetone solution, ultrasonically assisted cleaning for 20 minutes, and then put the carbon fiber cloth into a tube furnace with openings at both ends in the air atmosphere, heat treatment at 400°C for 30 minute;

b. By physical vapor deposition method, using Fe with a purity of 99.99% as the target material, the carbon fiber cloth is deposited by thermal evaporation. The thickness of the Fe film attached to the carbon fiber cloth is 5nm, and the carbon fiber cloth with the Fe catalyst attached is directly Send it into the chemical vapor deposition chamber, raise the temperature to 680°C at a heating rate of 50°C/min, and then pass in hydrogen with a flow rate of 80sccm for 2 minutes;

c. The carbon fiber cloth obtained by the physical vapor deposition method in step b is passed through the chemical vapor phase method, and the flow rate of nitrogen gas is 200 sccm as carrier gas, the flow rate of ethylene gas is 120 sccm as carbon source gas, and the flow rate of hydrogen gas is 50 sccm for reduction Gas, the reaction temperature is 700°C, the time is 15 minutes, and carbon nanotubes are grown in situ on the carbon fiber cloth;

d. Through the chemical vapor phase method, first use nitrogen as a carrier gas to flush the vapor deposition reaction chamber, the gas flow rate is 300 sccm, and the flushing time is 8 minutes. The purpose is to eliminate other gases in the reaction chamber and provide a clean environment for growing nano-titanium dioxide. Then the flow rate of nitrogen gas is 200 sccm as carrier gas, the flow rate of tetraisopropoxytitanium vapor is 50 sccm as titanium source gas, the reaction temperature is 430 ℃, and the time is 12 minutes to grow titanium dioxide nano-shells on the outside of carbon nanotubes. A composite nanostructured carbon fiber material is obtained, wherein the average length of the carbon nanotubes is 720 μm, and the average thickness of the nano-titanium dioxide shell around the carbon nanotubes is 5 nm, which is a single crystal anatase structure.

Example 3

a. Pretreatment of carbon fiber cloth: put 100×100 mm biaxial carbon fiber cloth into a sodium carbonate solution with a concentration of 40g/L, the solution temperature is 60°C, ultrasonic cleaning for 30 minutes, and deionized water After cleaning twice, put the carbon fiber cloth into the acetone solution, ultrasonically assisted cleaning for 20 minutes, and then put the carbon fiber cloth into a tube furnace with openings at both ends in the air atmosphere, heat treatment at 400°C for 30 minutes;

b. By the physical vapor deposition method, using Fe with a purity of 99.99% as the target material, the carbon fiber cloth is deposited by magnetron sputtering. The thickness of the Fe film attached to the carbon fiber cloth is 0.5 nm, and the carbon fiber cloth with the Fe catalyst attached is The cloth is directly sent into the chemical vapor deposition chamber, and the temperature is raised to 600°C at a heating rate of 50°C/min, and then hydrogen gas with a flow rate of 10 sccm is introduced for reduction for 2 minutes;

c. The carbon fiber cloth obtained by the physical vapor deposition method in step b is passed through the chemical vapor phase method, and the flow rate of nitrogen gas is 50 sccm as carrier gas, the flow rate of ethylene gas is 20 sccm as carbon source gas, and the flow rate of hydrogen gas is 5 sccm for reduction gas, the reaction temperature is 600°C, and the time is 1 minute to grow carbon nanotubes in situ on the carbon fiber cloth;

d. Through the chemical vapor phase method, first use argon as the carrier gas to flush the vapor deposition reaction chamber. The gas flow rate is 600 sccm, and the flushing time is 6 minutes. The purpose is to eliminate other gases in the reaction chamber and provide a clean environment for growing nano-titanium dioxide. , the flow rate of nitrogen gas is 50 sccm as carrier gas, the flow rate of tetraisopropoxytitanium vapor is 10 sccm as titanium source gas, the reaction temperature is 300 ° C, and the time is 5 minutes to grow titanium dioxide nano shells outside the carbon nanotubes, namely A composite nanostructured carbon fiber material can be obtained, in which the average length of the carbon nanotubes is 50 μm, and the average thickness of the nano-titanium dioxide shell around the carbon nanotubes is 6 nm, which is a single crystal anatase structure.

Example 4

a. Pretreatment of carbon fiber cloth: put a 120×120 mm triaxial carbon fiber cloth into a sodium carbonate solution with a concentration of 35g/L, the solution temperature is 60°C, and ultrasonically assisted cleaning for 30 minutes. After cleaning with deionized water, put the carbon fiber cloth into the acetone solution, ultrasonically assist cleaning for 20 minutes, and then put the carbon fiber cloth into a tube furnace with openings at both ends in the air atmosphere, heat treatment at 400°C for 30 minutes ;

b. By the liquid phase method, put the pretreated carbon fiber cloth into the FeCl ₃ solution with a concentration of 1.00 mol/L and impregnate it to obtain a layer of Fe catalyst attached to the carbon fiber cloth, and then pass clean air into the vapor deposition chamber, The Fe catalyst attached to the carbon fiber cloth was heat-treated at a temperature of 450°C for 15 minutes, then the temperature was raised to 700°C, and hydrogen gas with a flow rate of 100 sccm was introduced for reduction for 8 minutes;

c, the carbon fiber cloth obtained by the liquid phase method in step b is passed through the chemical vapor phase method, and the flow rate of argon gas is 500 sccm as the carrier gas, the flow rate of ethylene gas is 200 sccm as the carbon source gas, and the flow rate of hydrogen gas is 50 sccm as the carbon source gas. Reducing gas, the reaction temperature is 700°C, and the time is 30 minutes to grow carbon nanotubes in situ on the carbon fiber cloth;

d. Through the chemical vapor phase method, first use argon as a carrier gas to flush the vapor deposition reaction chamber, the gas flow rate is 600 sccm, and the flushing time is 7 minutes. The purpose is to exclude other gases in the reaction chamber and provide a clean environment for growing nano-titanium dioxide. Environment, the flow rate of argon gas is 300 sccm as the carrier gas, the flow rate of tetraisopropoxytitanium vapor is 250 sccm as the titanium source gas, the reaction temperature is 720 ℃, and the time is 30 minutes to grow titanium dioxide nanoshells outside the carbon nanotubes , the composite nanostructure carbon fiber material can be obtained, wherein the average length of the carbon nanotubes is 920 μm, and the average thickness of the nano-titanium dioxide shell around the carbon nanotubes is 25nm, which is a single crystal anatase structure.

Claims (1)

1. A preparation method for composite nanostructured carbon fiber material, characterized in that it is carried out in the following steps: a. Pretreatment of carbon fiber cloth: put the carbon fiber cloth into a sodium carbonate solution with a concentration of 20-40g/L at a temperature of 60°C, ultrasonically assisted cleaning for 30 minutes, and then clean with deionized water, then place the carbon fiber cloth into acetone solution, ultrasonically assisted cleaning for 20 minutes, and then heat-treat the carbon fiber cloth at 400°C for 30 minutes in an air atmosphere; b. Through the liquid phase method, put the pretreated carbon fiber cloth into the FeCl ₃ solution with a concentration of 0.05-1.00mol/L and impregnate it to obtain a layer of Fe catalyst attached to the carbon fiber cloth, and then pass clean air into the vapor deposition chamber , heat-treating the Fe catalyst attached to the carbon fiber cloth at a temperature of 450°C for 15 minutes, then raising the temperature to 650-700°C, and passing in hydrogen with a flow rate of 30-100 sccm for 2-8 minutes; Or through the physical vapor deposition method, using Fe with a purity of 99.99% as the target material, the carbon fiber cloth is deposited by magnetron sputtering or thermal evaporation, and the thickness of the Fe film attached to the carbon fiber cloth is 0.5-8nm. The carbon fiber cloth of the Fe catalyst is directly sent into the chemical vapor deposition chamber, and the temperature is raised to 600-700°C at a heating rate of 50°C/min, and then hydrogen gas with a flow rate of 10-80sccm is introduced for reduction for 2-8 minutes; c. The carbon fiber cloth obtained by liquid phase method or physical vapor deposition method in step b is subjected to chemical vapor phase method, using argon or nitrogen as carrier gas, ethylene or acetylene gas as carbon source gas, hydrogen as reducing gas, and reacting The temperature is 600-700°C, and the time is 1-30 minutes to grow carbon nanotubes in situ on the carbon fiber cloth. The flow rate of argon or nitrogen as the carrier gas is 50-500 sccm, and the flow rate of ethylene or acetylene gas as the carbon source gas is 20-200 sccm, the flow rate of hydrogen as reducing gas is 5-50 sccm; d. Through the chemical vapor phase method, first use argon or nitrogen as the carrier gas to flush the vapor deposition reaction chamber, the gas flow rate is 300-600sccm, and the flushing time is 5-8 minutes, and then use argon or nitrogen as the flow rate of the carrier gas It is 50-300sccm, the flow rate of titanium source gas is 10-250sccm with tetraisopropoxytitanium vapor, the reaction temperature is 300-720°C, and the time is 5-30 minutes to grow titanium dioxide nano shells outside the carbon nanotubes, that is A composite nanostructured carbon fiber material can be obtained.