A nickel metalloene-modified composite carbon fiber and preparation method thereof

Abstract

The present invention discloses a composite carbon fiber modified with nickel metal and a preparation method thereof. The preparation method of the composite carbon fiber modified with nickel metal of the present invention comprises the following steps: (1) roughening and modifying the carbon fiber with an etching solution to obtain an etching-modified carbon fiber; (2) modifying the surface of the etching-modified carbon fiber with graphene oxide to obtain a graphene oxide-modified carbon fiber; (3) activating the graphene oxide-modified carbon fiber and then performing chemical nickel plating; and then performing reduction heating to reduce the graphene oxide on the surface of the carbon fiber to obtain a composite carbon fiber modified with nickel metal. The composite carbon fiber modified with nickel metal of the present invention is prepared by the above-mentioned preparation method, has high electrical conductivity as a whole, and can be used as a radar stealth flexible material.

Description

Technical Field

[0001] The invention relates to the technical field of modified carbon fiber materials, and in particular to a nickel metal-modified composite carbon fiber and a preparation method thereof. Background Art

[0002] Carbon fiber has excellent properties such as high strength, high modulus, corrosion resistance, high temperature resistance, good electrical conductivity, and heat insulation. It has become a high-tech fiber that my country is vigorously developing at this stage, and has broad application prospects in the fields of national defense, military industry, aerospace, and civil use. In recent years, carbon fiber has become an important reinforcing material for filling metal, ceramic and resin-based composite materials, and has broad application prospects in the fields of aerospace, electromagnetic shielding, electronics industry, civil engineering, etc. However, the surface inertness of carbon fiber is large, and the adhesion and wettability with the matrix are poor, which limits its application to a certain extent. Among them, metallization modification of carbon fiber surface is one of the effective methods to change the surface properties and structure, realize the control of carbon fiber surface, and improve the surface activity of carbon fiber and its compatibility with other materials. Carbon fiber with surface metal modification can not only effectively combine with the matrix material, but also greatly improve the electrical conductivity. It is widely used in electromagnetic shielding materials, radar stealth and interference materials, large-capacity capacitors and other electronic functional devices.

[0003] The main methods for carbon fiber surface metallization include electroplating, chemical plating, magnetron sputtering, and vapor deposition. Among them, chemical plating is easy to operate, has simple equipment, uniform coating, low porosity, and can deposit metal particles on the surface of non-metallic materials with complex shapes. It is widely used. Before chemical plating, the carbon fiber surface needs to be pretreated in a series of ways. The commonly used pretreatment procedures are: degumming → degreasing → roughening → sensitization → activation. However, this type of pretreatment procedure will bring about environmental pollution problems such as the difficulty in handling chemical waste liquids, which hinders the industrial development of chemical plating. Among them, the roughening process uses strong oxidants such as strong acids to etch the carbon fiber surface to obtain a rough surface microstructure, but the strength and modulus of the fiber are significantly reduced. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of severe strong acid etching during surface pretreatment of existing modified carbon fibers during chemical plating, resulting in a significant decrease in strength and modulus, uneven deposition, and the like. A method for preparing composite carbon fibers modified with nickel metal is provided, specifically a process for modifying the surface of carbon fibers with graphene oxide by nickel plating, wherein the surface of the carbon fibers is modified with graphene oxide, and nickel is further chemically plated on the surface of the graphene oxide-modified carbon fibers and the graphene oxide is reduced by heating to improve the conductivity of the carbon fibers, so as to prepare composite carbon fibers coated with nickel / reduced graphene oxide.

[0005] Another object of the present invention is to provide nickel metal modified composite carbon fiber prepared by the above preparation method.

[0006] The purpose of the present invention is achieved through the following technical solutions.

[0007] A method for preparing a nickel metal-modified composite carbon fiber comprises the following steps:

[0008] (1) roughening and modifying the carbon fiber using an etching solution to obtain etching-modified carbon fiber;

[0009] (2) modifying the surface of the etched and modified carbon fiber with graphene oxide to obtain a carbon fiber modified with graphene oxide;

[0010] (3) After activating the carbon fiber modified with graphene oxide, chemically nickel-plating is performed; and then reduction heating is performed to reduce the graphene oxide on the surface of the carbon fiber to obtain a composite carbon fiber modified with nickel metal.

[0011] In a preferred embodiment, before the carbon fibers are roughened and modified, the carbon fibers are subjected to a desizing and washing treatment, and then roughened and modified using an etching solution after being dried.

[0012] Further preferably, the desizing and washing treatment is: soaking the carbon fiber in an acetone solution for 12 to 24 hours at a soaking temperature of 60 to 80° C., and then repeatedly cleaning with anhydrous ethanol and deionized water to remove impurities on the surface of the carbon fiber.

[0013] More preferably, the drying is performed at 60-80° C. in vacuum for 2-4 hours.

[0014] Preferably, in step (1), the etching solution is an acid solution, including one or more of nitric acid, sulfuric acid, ammonium persulfate solution and potassium dichromate solution, more preferably dilute nitric acid.

[0015] Preferably, in step (1), the roughening modification is carried out at a temperature of 60 to 80° C. and for a time of 60 to 120 minutes.

[0016] Preferably, in step (2), modifying the surface of the etched modified carbon fiber with graphene oxide comprises: using a graphene oxide dispersion as a modification liquid, coating or depositing graphene oxide on the surface of the etched modified carbon fiber by dip coating or electrophoretic deposition.

[0017] Among them, the dip coating is to immerse the carbon fiber in a graphene oxide dispersion, thereby coating the surface of the carbon fiber to form a graphene oxide coating layer; the electrophoretic deposition is to deposit the graphene oxide in the graphene oxide dispersion on the surface of the carbon fiber through electrophoresis, thereby forming a graphene oxide deposition layer on the surface of the carbon fiber.

[0018] Further preferably, the graphene oxide dispersion is prepared by dissolving graphene oxide with a solid content of 2 mg / ml in deionized water or ethanol to form a graphene oxide dispersion with a concentration of 0.2 to 0.5 mg / ml, and after ultrasonic dispersion for 30 to 60 minutes, NaOH or KOH is used to adjust the pH value to 8 to 10.

[0019] Further preferably, the graphene oxide used to prepare the graphene oxide dispersion is self-made by exfoliating graphite flakes using the Hummer method, or is a commercially available product.

[0020] More preferably, the immersion coating is carried out at a temperature of 40 to 60° C. for 3 to 6 hours.

[0021] In some specific preferred embodiments, during the dip coating, the surface of the etched modified carbon fiber is amino functionalized, and the amino functionalization treatment of graphene oxide can improve the bonding force between graphene oxide and carbon fiber, thereby enhancing the physical adsorption bonding force between graphene oxide and the surface of carbon fiber. The amino functionalization dip coating of graphene oxide includes:

[0022] The graphene oxide and the siloxane coupling agent are mixed, and ultrasonicated at 50 to 30° C. for 2 to 5 hours to prepare an amine-functionalized graphene oxide solution, and the etched modified carbon fiber is impregnated and coated with the amine-functionalized graphene oxide solution;

[0023] The pH value of the amino-functionalized graphene oxide solution is 8-10, wherein the solid content of the graphene oxide is 0.2-0.5 mg / ml, and the mass concentration of the siloxane coupling agent is 5-10%; the temperature of the immersion coating is 40-60° C., and the time is 3-6 hours.

[0024] In some other specific preferred embodiments, the amine-functionalized dip coating of graphene oxide comprises:

[0025] Under ultrasonic treatment, the etched modified carbon fiber is first immersed in a siloxane coupling agent solution, and then immersed in the graphene oxide dispersion to graft graphene oxide on the surface of the carbon fiber;

[0026] Among them, first prepare a siloxane coupling agent solution with a mass concentration of 5-10%, and stir it magnetically at room temperature for 20-30 minutes; the immersion temperature in the siloxane coupling agent solution is 30-60°C, and the immersion time is 30-60 minutes; the concentration of the graphene oxide dispersion is 0.2-0.5 mg / ml, the pH value is 8-10, the immersion temperature in the graphene oxide dispersion is 40-60°C, and the immersion time is 3-6 hours.

[0027] The electrophoretic deposition method can solve the agglomeration problem when graphene oxide is grafted onto carbon fiber, and has high production efficiency, economy and environmental protection.

[0028] Further preferably, the electrophoretic deposition uses a graphene oxide dispersion with a concentration of 1 to 2 mg / ml as the electrophoretic liquid, the etched modified carbon fiber is connected to the negative pole of the power supply, the DC output voltage is 5 to 60 V, the electrophoretic deposition time is 10 to 60 minutes, and the electrophoretic deposition temperature is 30 to 30°C.

[0029] Further preferably, the electrophoretic deposition is performed using a Hastelloy cell, and the electrophoretic deposition temperature is controlled and heated by a heating rod in the Hastelloy cell.

[0030] Further preferably, the etched modified carbon fiber is modified with graphene oxide by dip coating or electrophoretic deposition, and then dried before the operation of step (3) is performed. The drying is vacuum drying at 80-100°C.

[0031] Preferably, in step (3), the activation is to immerse the graphene oxide modified carbon fiber in a metal salt solution, and use a reducing agent to reduce the metal ions in the metal salt solution and attach them to the surface of the graphene oxide modified carbon fiber to complex the metal ions.

[0032] More preferably, the metal salt is silver nitrate, palladium chloride or tetrachloropalladium(II) acid.

[0033] Further preferably, the reducing agent is one or more of sodium hypochlorite, sodium citrate and dimethylaminoborane (DMAB).

[0034] Further preferably, the concentration of the metal salt solution is 0.001-0.005 mol / L, and the concentration of the reducing agent in the metal salt solution is 0.01-0.05 mol / L.

[0035] More preferably, the complexing temperature is 30-50° C. and the time is 5-30 min.

[0036] More preferably, the reduction temperature is 30-50° C. and the time is 5-30 min.

[0037] Preferably, in step (3), the chemical nickel plating utilizes a reduction reaction to reduce and deposit metal nickel ions on the surface of the activated graphene oxide-modified carbon fiber to perform nickel plating.

[0038] Further preferably, in step (3), the chemical nickel plating is:

[0039] Under the temperature condition of 60-80° C., the activated graphene oxide modified carbon fiber is immersed in a nickel solution with a reducing agent added, and the pH value is adjusted to 8-10 with NaOH or ammonia water, and the reaction is stirred for 10-30 minutes.

[0040] Further preferably, the nickel solution is composed of: 25-40 g / L nickel salt, 10-20 g / L sodium citrate, 10-30 g / L reducing agent, 5-10 g / L ammonium chloride, 1-2 mg / L thiourea, and the balance is deionized water.

[0041] Further preferably, the nickel salt is one or more of nickel sulfate, nickel chloride, nickel hypophosphite and nickel nitrate.

[0042] Further preferably, the reducing agent is one or both of sodium hypophosphite and dimethylaminoborane.

[0043] More preferably, the total time for the chemical nickel plating is 20 to 40 minutes.

[0044] Preferably, in step (3), the reduction heating is performed from room temperature to 400-600°C at a heating rate of 1-3°C / min, and after being kept at this temperature for 10-20 minutes, the temperature is naturally cooled to room temperature.

[0045] Preferably, in step (3), the reduction heating is carried out under a protective atmosphere of argon, hydrogen or an argon / hydrogen mixture, with a ventilation rate of 100 to 300 ml / min.

[0046] Preferably, in step (3), the reduction heating is carried out in a tubular atmosphere furnace.

[0047] A nickel metal modified composite carbon fiber is prepared by any of the methods described above.

[0048] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0049] The method for preparing the composite carbon fiber modified by nickel metal of the present invention sequentially performs graphene oxide modification, activation treatment, chemical nickel plating, and heating reduction treatment on the carbon fiber modified by etching and roughening, thereby modifying graphene oxide on the surface of the carbon fiber and plating nickel to prepare the composite carbon fiber coated with nickel / reduced graphene oxide. Among them, after the carbon fiber surface is modified with graphene oxide, a graphene oxide layer is formed to improve the conductivity of the carbon fiber; the active functional group catalytic fixation of graphene oxide can effectively anchor and activate precious metal ions, thereby further improving the bonding force between the metal nickel layer and the carbon fiber; the graphene oxide is reduced by high temperature heating, and the reduced graphene oxide formed has a higher conductivity, further improving the conductivity of the carbon fiber as a whole; and the nickel metal layer has good magnetic permeability.

[0050] The nickel metal-modified composite carbon fiber of the present invention is prepared by the above-mentioned method for preparing the nickel metal-modified composite carbon fiber, has high electrical conductivity as a whole, and can be used as a radar stealth flexible material. DETAILED DESCRIPTION

[0051] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments, but the protection scope and implementation mode of the present invention are not limited thereto. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0052] And, unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0053] It should be understood that the singular forms used in the present invention, such as "a", include plural references unless otherwise specified. In addition, the terms "including", "containing", and "having" are open-ended definitions rather than closed-ended definitions, that is, they include the contents specified in the present invention, but do not exclude other aspects. In other words, the terms also include "essentially consisting of" or "consisting of".

[0054] In addition, "and combinations thereof" in the specification refers to any combination of all listed items. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0055] Unless otherwise specified, all technical and scientific terms used herein have the standard meanings in the field to which the claimed subject matter belongs. If there are multiple definitions for a term, the definition herein shall prevail.

[0056] Unless otherwise indicated, this invention employs standard nomenclature and standard laboratory procedures and techniques of analytical chemistry, synthetic organic chemistry, and optics.

[0057] Without violating the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0058] The technical solution of the present invention is described in detail below in conjunction with specific embodiments.

[0059] In a specific embodiment of the present invention, the preparation of the composite carbon fiber modified with nickel metal comprises the following specific steps:

[0060] (1) Desizing and washing: desizing, washing and drying the carbon fiber;

[0061] (2) Surface etching modification: The desizing carbon fiber is immersed in an etching solution for roughening modification, then neutralized with an alkali solution, taken out, washed, and dried;

[0062] (3) Preparation of graphene oxide solution: dispersing graphene oxide in water or ethanol to prepare a graphene oxide dispersion;

[0063] (4) coating and deposition: using the graphene oxide dispersion of step (3) as a modification solution, coating or depositing graphene oxide on the surface of the carbon fiber treated in step (2) by dip coating or electrophoretic deposition, taking out, washing and drying;

[0064] (5) Activation: activating the carbon fiber modified with graphene oxide in an activation solution, taking it out, washing it, and drying it;

[0065] (6) Chemical nickel plating: immersing the carbon fiber treated in step (5) in a nickel ion solution for reduction, performing chemical nickel plating, taking out, washing, and drying;

[0066] (3) High-temperature reduction: The carbon fiber after chemical nickel plating in step (6) is heated at high temperature in a reducing protective atmosphere to reduce the graphene oxide on the surface of the carbon fiber at high temperature, thereby completing the preparation of the composite carbon fiber modified with nickel metal.

[0067] In the following examples, the specific sources of raw materials used are:

[0068] Graphene oxide: commercially available product S926158 from Shanghai MacLean Biochemical Technology Co., Ltd.

[0069] Silane coupling agent KH550: γ-aminopropyltriethoxysilane, commercially available product A800523 from Shanghai MacLean Biochemical Technology Co., Ltd.

[0070] Example 1

[0071] The nickel metal-modified composite carbon fiber of this embodiment is specifically prepared in the following steps:

[0072] (1) Place the carbon fiber in an acetone solution (99.5%, analytical grade), soak it in a water bath at 60°C for 24 hours, wash it repeatedly with anhydrous ethanol and deionized water, and then dry it at 60°C for 2 hours for standby use;

[0073] (2) preparing 200 ml of 15% nitric acid solution in a beaker, immersing the cleaned and dried carbon fiber in step (1) in the beaker, and heating in a water bath at 80° C. for 60 minutes, taking out, and immersing in a 10% NaOH solution for 5 minutes, taking out, washing with deionized water and drying at 60° C.;

[0074] (3) adding 2 mg / ml graphene oxide commercially available from McLean to deionized water to prepare a 1 mg / ml graphene oxide solution, performing ultrasonic dispersion at room temperature for 60 minutes, and adjusting the pH value of the dispersion to pH=10 with NaOH to obtain a graphene oxide dispersion;

[0075] (4) adding the graphene oxide dispersion obtained in step (3) into a Hastelloy trough as an electrophoresis solution, connecting the carbon fiber treated in step (2) to the negative electrode of the power supply, connecting the platinum electrode to the positive electrode of the power supply, and placing them together in the electrophoresis solution, wherein the distance between the carbon fiber and the platinum electrode is 1 cm, the DC voltage of the power supply is 10 V, the electrophoresis temperature is 30° C., the electrophoresis deposition time is 50 minutes, and the prepared carbon fiber with deposited graphene oxide is placed in a drying oven at 80° C. for drying;

[0076] (5) preparing 100 ml of a PdCl2 solution with a concentration of 0.001 mol / L, and immersing the cleaned and dried carbon fiber in the solution for 10 minutes at a complexing temperature of 40°C; then adding 0.05 mol / L sodium citrate for reduction for 10 minutes at a reduction temperature of 40°C;

[0077] (6) preparing a mixed plating solution containing 30 g / L nickel sulfate, 20 g / L sodium citrate, 25 g / L sodium hypophosphite, 5 g / L ammonium chloride, and 1 mg / L thiourea, immersing the carbon fiber treated in step (5) in the mixed plating solution, adjusting the pH value of the mixed plating solution to 8, and stirring at 80° C. for 20 minutes; taking out, washing with deionized water, and drying to obtain nickel / graphene oxide modified carbon fiber;

[0078] (3) The carbon fiber modified with nickel / graphene oxide was placed in an argon-protected tubular atmosphere furnace with a ventilation rate of 100 ml / min, and the temperature was increased from room temperature to 500°C at a heating rate of 1°C / min. After keeping warm for 10 minutes, it was naturally cooled to room temperature to reduce the graphene oxide coated on the carbon fiber to graphene, thereby preparing the nickel metal-modified composite carbon fiber of this embodiment.

[0079] The line resistance of the nickel metal-modified composite carbon fiber prepared in this embodiment was tested with a digital multimeter and found to be 4.5 Ω / cm.

[0080] Example 2

[0081] The nickel metal-modified composite carbon fiber of this embodiment is specifically prepared in the following steps:

[0082] (1) Place the carbon fiber in an acetone solution (99.5%, analytical grade), soak it in a water bath at 60°C for 24 hours, wash it repeatedly with anhydrous ethanol and deionized water, and then dry it at 60°C for 2 hours for standby use;

[0083] (2) preparing 200 ml of 15% nitric acid solution in a beaker, immersing the cleaned and dried carbon fiber in step (1) in the beaker, and heating in a water bath at 80° C. for 60 minutes, taking out, and immersing in a 10% NaOH solution for 5 minutes, taking out, washing with deionized water and drying at 60° C.;

[0084] (3) preparing a KH550 solution with a mass ratio of 9%, magnetically stirring for 30 minutes, placing the carbon fiber in the solution, sealing and heating at 40°C for 30 minutes, taking it out, washing it with deionized water and drying it at 60°C;

[0085] (4) adding 2 mg / ml graphene oxide commercially available from McLean to deionized water to prepare a 0.2 mg / ml graphene oxide solution, dispersing by ultrasonic at room temperature for 60 minutes, and adjusting the pH value of the dispersion to pH=10 with NaOH to obtain a graphene oxide dispersion;

[0086] The carbon fiber modified with KH500 in step (3) was immersed in a graphene oxide dispersion, and subjected to ultrasonic treatment for 6 hours at a temperature of 60° C.; taken out, washed with deionized water, and dried at 60° C.;

[0087] (5) preparing 100 ml of a PdCl2 solution with a concentration of 0.001 mol / L, and immersing the cleaned and dried carbon fiber in the solution for 10 minutes at a complexing temperature of 40°C; then adding 0.05 mol / L sodium citrate for reduction for 10 minutes at a reduction temperature of 40°C;

[0088] (6) preparing a mixed plating solution containing 30 g / L nickel sulfate, 20 g / L sodium citrate, 25 g / L sodium hypophosphite, 5 g / L ammonium chloride, and 1 mg / L thiourea, immersing the carbon fiber treated in step (5) in the mixed plating solution, adjusting the pH value of the mixed plating solution to 8, and stirring at 80° C. for 20 minutes; taking out, washing with deionized water, and drying to obtain nickel / graphene oxide modified carbon fiber;

[0089] (3) The carbon fiber modified with nickel / graphene oxide was placed in an argon-protected tubular atmosphere furnace with a ventilation rate of 100 ml / min, and the temperature was increased from room temperature to 500°C at a heating rate of 1°C / min. After keeping warm for 10 minutes, it was naturally cooled to room temperature to reduce the graphene oxide coated on the carbon fiber to graphene, thereby preparing the nickel metal-modified composite carbon fiber of this embodiment.

[0090] The line resistance of the nickel metal-modified composite carbon fiber prepared in this embodiment was tested with a digital multimeter and found to be 3.6 Ω / cm.

[0091] Example 3

[0092] The nickel metal-modified composite carbon fiber of this embodiment is specifically prepared in the following steps:

[0093] (1) Place the carbon fiber in an acetone solution (99.5%, analytical grade), soak it in a water bath at 60°C for 24 hours, wash it repeatedly with anhydrous ethanol and deionized water, and then dry it at 60°C for 2 hours for standby use;

[0094] (2) preparing 200 ml of 15% nitric acid solution in a beaker, immersing the cleaned and dried carbon fiber in step (1) in the beaker, and heating in a water bath at 80° C. for 60 minutes, taking out, and immersing in a 10% NaOH solution for 5 minutes, taking out, washing with deionized water and drying at 60° C.;

[0095] (3) preparing a mixed solution of KH550 (mass concentration 9%) and graphene oxide (mass concentration 0.2 mg / L), ultrasonicating at 60° C. for 2 h to prepare an amine-functionalized graphene oxide solution, and adjusting the pH value to 8;

[0096] (4) using the amino-functionalized graphene oxide solution to dip-coat the carbon fiber etched and modified in step (2), the dip-coating temperature being 50° C. and the dip-coating time being 4 hours;

[0097] (5) preparing 100 ml of a PdCl2 solution with a concentration of 0.001 mol / L, and immersing the cleaned and dried carbon fiber in the solution for 10 minutes at a complexing temperature of 40°C; then adding 0.05 mol / L sodium citrate for reduction for 10 minutes at a reduction temperature of 40°C;

[0098] (6) preparing a mixed plating solution containing 30 g / L nickel sulfate, 20 g / L sodium citrate, 25 g / L sodium hypophosphite, 5 g / L ammonium chloride, and 1 mg / L thiourea, immersing the carbon fiber treated in step (5) in the mixed plating solution, adjusting the pH value of the mixed plating solution to 8, and stirring at 80° C. for 20 minutes; taking out, washing with deionized water, and drying to obtain nickel / graphene oxide modified carbon fiber;

[0099] (3) The carbon fiber modified with nickel / graphene oxide was placed in an argon-protected tubular atmosphere furnace with a ventilation rate of 100 ml / min, and the temperature was increased from room temperature to 500°C at a heating rate of 1°C / min. After keeping warm for 10 minutes, it was naturally cooled to room temperature to reduce the graphene oxide coated on the carbon fiber to graphene, thereby preparing the nickel metal-modified composite carbon fiber of this embodiment.

[0100] The line resistance of the nickel metal-modified composite carbon fiber prepared in this embodiment was tested with a digital multimeter and found to be 3.9 Ω / cm.

[0101] Example 4

[0102] The nickel metal-modified composite carbon fiber of this embodiment is specifically prepared in the following steps:

[0103] (1) Place the carbon fiber in an acetone solution (99.5%, analytical grade), soak it in a water bath at 60°C for 24 hours, wash it repeatedly with anhydrous ethanol and deionized water, and then dry it at 60°C for 2 hours for standby use;

[0104] (2) preparing 200 ml of 15% nitric acid solution in a beaker, immersing the cleaned and dried carbon fiber in step (1) in the beaker, and heating in a water bath at 80° C. for 60 minutes, taking out, and immersing in a 10% NaOH solution for 5 minutes, taking out, washing with deionized water and drying at 60° C.;

[0105] (3) preparing a KH550 solution with a mass ratio of 9%, magnetically stirring for 30 minutes, placing the carbon fiber in the solution, sealing and heating at 40°C for 30 minutes, taking it out, washing it with deionized water and drying it at 60°C;

[0106] (4) adding 2 mg / ml graphene oxide commercially available from McLean to deionized water to prepare a 0.2 mg / ml graphene oxide solution, dispersing by ultrasonic at room temperature for 60 minutes, and adjusting the pH value of the dispersion to pH=10 with NaOH to obtain a graphene oxide dispersion;

[0107] The carbon fiber modified with KH500 in step (3) was immersed in a graphene oxide dispersion, and subjected to ultrasonic treatment for 6 hours at a temperature of 60° C.; taken out, washed with deionized water, and dried at 60° C.;

[0108] (5) preparing 100 ml of a PdCl2 solution with a concentration of 0.001 mol / L, and immersing the cleaned and dried carbon fiber in the solution for 10 minutes at a complexing temperature of 40°C; then adding 0.05 mol / L sodium citrate for reduction for 10 minutes at a reduction temperature of 40°C;

[0109] (6) preparing a mixed plating solution containing 30 g / L nickel sulfate, 20 g / L sodium citrate, 25 g / L sodium hypophosphite, 5 g / L ammonium chloride, and 1 mg / L thiourea, immersing the carbon fiber treated in step (5) in the mixed plating solution, adjusting the pH value of the mixed plating solution to 8, and stirring at 30° C. for 30 minutes; taking out, washing with deionized water, and drying to obtain nickel / graphene oxide modified carbon fiber;

[0110] (3) The carbon fiber modified with nickel / graphene oxide is placed in an argon-protected tubular atmosphere furnace with a ventilation rate of 300 ml / min, and the temperature is increased from room temperature to 600°C at a heating rate of 1°C / min. After keeping warm for 10 minutes, it is naturally cooled to room temperature to reduce the graphene oxide coated on the carbon fiber to graphene, thereby preparing the nickel metal-modified composite carbon fiber of this embodiment.

[0111] The line resistance of the nickel metal-modified composite carbon fiber prepared in this embodiment was tested with a digital multimeter and found to be 2.4 Ω / cm.

[0112] Comparative Example 1

[0113] The nickel metal-modified composite carbon fiber of this comparative example is specifically prepared in the following steps:

[0114] (1) Place the carbon fiber in an acetone solution (99.5%, analytical grade), soak it in a water bath at 60°C for 24 hours, wash it repeatedly with anhydrous ethanol and deionized water, and then dry it at 60°C for 2 hours for standby use;

[0115] (2) preparing 200 ml of 15% nitric acid solution in a beaker, immersing the cleaned and dried carbon fiber in step (1) in the beaker, and heating in a water bath at 80° C. for 60 minutes, taking out, and immersing in a 10% NaOH solution for 5 minutes, taking out, washing with deionized water and drying at 60° C.;

[0116] (3) preparing 100 ml of a PdCl2 solution with a concentration of 0.001 mol / L, and immersing the cleaned and dried carbon fiber in the solution for 10 minutes at a complexing temperature of 40°C; then adding 0.05 mol / L sodium citrate for reduction for 10 minutes at a reduction temperature of 40°C;

[0117] (4) preparing a mixed plating solution containing 30 g / L nickel sulfate, 20 g / L sodium citrate, 25 g / L sodium hypophosphite, 8 g / L ammonium chloride, and 1 mg / L thiourea, immersing the carbon fiber treated in step (3) in the mixed plating solution, adjusting the pH value of the mixed plating solution to 8, and stirring at 80° C. for 20 minutes; taking out, washing with deionized water, and drying to obtain nickel-modified carbon fiber.

[0118] (5) The nickel-modified carbon fiber was placed in an argon-protected tubular atmosphere furnace with a ventilation rate of 100 ml / min, and the temperature was increased from room temperature to 500°C at a heating rate of 1°C / min. After keeping the temperature for 10 minutes, the carbon fiber was naturally cooled to room temperature to prepare the composite carbon fiber modified with nickel metal in this comparative example.

[0119] The line resistance value of the nickel metal-modified composite carbon fiber prepared in this comparative example was tested by a digital multimeter and was found to be 8.3 Ω / cm.

[0120] Comparative Example 2

[0121] The nickel metal-modified composite carbon fiber of this embodiment is specifically prepared in the following steps:

[0122] (1) Place the carbon fiber in an acetone solution (99.5%, analytical grade), soak it in a water bath at 60°C for 24 hours, wash it repeatedly with anhydrous ethanol and deionized water, and then dry it at 60°C for 2 hours for standby use;

[0123] (2) preparing a KH550 solution with a mass ratio of 9%, magnetically stirring for 30 minutes, placing the carbon fiber in the solution, sealing and heating at 40°C for 30 minutes, taking it out, washing it with deionized water and drying it at 60°C;

[0124] (3) adding 2 mg / ml graphene oxide commercially available from McLean to deionized water to prepare a 1 mg / ml graphene oxide solution, performing ultrasonic dispersion at room temperature for 60 minutes, and adjusting the pH value of the dispersion to pH=10 with NaOH to obtain a graphene oxide dispersion;

[0125] The carbon fiber modified with KH500 in step (2) was immersed in a graphene oxide dispersion, and subjected to ultrasonic treatment for 6 hours at a temperature of 60° C.; taken out, washed with deionized water, and dried at 60° C.;

[0126] (4) preparing 100 ml of a PdCl2 solution with a concentration of 0.001 mol / L, and immersing the cleaned and dried carbon fiber in the solution for 10 minutes at a complexing temperature of 40°C; then adding 0.05 mol / L sodium citrate for reduction for 10 minutes at a reduction temperature of 40°C;

[0127] (5) preparing a mixed plating solution containing 30 g / L nickel sulfate, 20 g / L sodium citrate, 25 g / L sodium hypophosphite, 8 g / L ammonium chloride, and 1 mg / L thiourea, immersing the carbon fiber treated in step (4) in the mixed plating solution, adjusting the pH value of the mixed plating solution to 8, and stirring at 80° C. for 20 minutes; taking out, washing with deionized water, and drying to obtain nickel / graphene oxide modified carbon fiber;

[0128] (6) The carbon fiber modified with graphene oxide / nickel is placed in an argon-protected tubular atmosphere furnace with a ventilation rate of 100 ml / min, and the temperature is increased from room temperature to 500°C at a heating rate of 1°C / min. After keeping warm for 10 minutes, it is naturally cooled to room temperature to reduce the graphene oxide coated on the carbon fiber to graphene, thereby preparing the nickel metal-modified composite carbon fiber of this comparative example.

[0129] The line resistance value of the nickel metal modified composite carbon fiber prepared above was tested by using a digital multimeter and was found to be 14.6 Ω / cm.

[0130] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, this specification does not describe all possible combinations of the technical features in the above-mentioned embodiments. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. Moreover, the above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the invention patent.

[0131] It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these modifications and improvements all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a nickel metal-modified composite carbon fiber, characterized in that: The steps include: (1) roughening and modifying the carbon fiber using an etching solution to obtain etching-modified carbon fiber; (2) modifying the surface of the etched and modified carbon fiber with graphene oxide to obtain a carbon fiber modified with graphene oxide; (3) activating the carbon fiber modified with graphene oxide and then performing chemical nickel plating; then performing reduction heating to reduce the graphene oxide on the surface of the carbon fiber to obtain a composite carbon fiber modified with nickel metal; In step (2), modifying the surface of the etched modified carbon fiber with graphene oxide comprises: first immersing the etched modified carbon fiber in a siloxane coupling agent solution, then immersing it in the graphene oxide dispersion, and coating the surface of the etched modified carbon fiber with graphene oxide; The mass concentration of the siloxane coupling agent solution is 5-10%, the immersion temperature in the siloxane coupling agent solution is 30-60° C., and the immersion time is 30-60 minutes; the concentration of the graphene oxide dispersion is 0.2-0.5 mg / ml, the pH value is 8-10, the immersion temperature in the graphene oxide dispersion is 40-60° C., and the immersion time is 3-6 hours; In step (3), the reduction heating is performed from room temperature to 400-600°C at a heating rate of 1-3°C / min, and the temperature is kept at this temperature for 10-20 minutes, and then the temperature is naturally cooled to room temperature.

2. The method for preparing the nickel metal-modified composite carbon fiber according to claim 1, characterized in that: In step (1), the etching solution is an acid solution, including one or more of nitric acid, sulfuric acid, ammonium persulfate solution and potassium dichromate solution; the temperature of the roughening modification is 60 to 80° C., and the time is 60 to 120 minutes.

3. The method for preparing the nickel metal-modified composite carbon fiber according to claim 1, characterized in that: In step (3), the activation is to immerse the graphene oxide modified carbon fiber in a metal salt solution, and use a reducing agent to reduce the metal ions in the metal salt solution and attach them to the surface of the graphene oxide modified carbon fiber to complex the metal ions; The metal salt is silver nitrate, palladium chloride or tetrachloropalladium (II) acid, and the reducing agent is one or more of sodium hypochlorite, sodium citrate and dimethylamino borane; the concentration of the metal salt solution is 0.001-0.005 mol / L, and the concentration of the reducing agent in the metal salt solution is 0.01-0.05 mol / L.

4. The method for preparing the nickel metal-modified composite carbon fiber according to claim 3, characterized in that: The complexing temperature is 30-50° C., and the time is 5-30 min; and / or, the reduction temperature is 30-50° C., and the time is 5-30 min.

5. The method for preparing nickel metal-modified composite carbon fiber according to claim 1, characterized in that: In step (3), the chemical nickel plating is as follows: at a temperature of 60 to 80° C., the activated graphene oxide-modified carbon fiber is immersed in a nickel solution to which a reducing agent is added, and the pH value is adjusted to 8 to 10 using NaOH or ammonia water, and the reaction is stirred for 10 to 30 minutes.

6. The method for preparing the nickel metal-modified composite carbon fiber according to claim 5, characterized in that: The nickel solution with the added reducing agent is composed of: 25-40 g / L nickel salt, 10-20 g / L sodium citrate, 10-30 g / L reducing agent, 5-10 g / L ammonium chloride, 1-2 mg / L thiourea, and the balance is deionized water; the nickel salt is one or more of nickel sulfate, nickel chloride, nickel hypophosphite and nickel nitrate, and the reducing agent is one or two of sodium hypophosphite and dimethylamino borane.

7. The method for preparing nickel metal-modified composite carbon fibers according to claim 5 or 6, characterized in that: The total time for the chemical nickel plating is 20 to 40 minutes.

8. The method for preparing nickel metal-modified composite carbon fibers according to claim 1, characterized in that: In step (3), the reduction heating is carried out under a protective atmosphere of argon, hydrogen or an argon / hydrogen mixture, and the ventilation rate is 100 to 300 ml / min.

9. A nickel metal modified composite carbon fiber, characterized in that: The method is prepared by any one of claims 1 to 8.