Technology for repairing holes and cracks on surface of carbon fiber by using graphene films

Abstract

A technology for repairing holes and cracks on the surface of carbon fiber by using graphene films comprises the following steps: cleaning carbon fiber with a nitric acid aqueous solution, immersing the carbon fiber in a hydrogen peroxide solution, performing oxidation treatment in an ultrasonic instrument, washing the surface of the carbon fiber with deionized water, and placing the carbon fiberin an oven for baking; then, sending the baked carbon fiber into a horizontal chemical vapor deposition furnace, performing vacuumizing treatment on the chemical vapor deposition furnace, introducingargon, and then, turning on a heating device for heating; introducing argon for annealing, and continuously drawing the carbon fiber; then, switching the argon into methane and hydrogen for growth, and continuously drawing the carbon fiber; finally, removing the hydrogen and performing cooling; then, removing methane, and decreasing the temperature to room temperature or keeping the temperature atconstant temperature of 30-37 DEG C. Structure defects on the surface of the carbon fiber are repaired by graphene, the strength of the carbon fiber is improved, and effects and efficiency both adaptto industrial implementation.

Description

technical field [0001] The invention belongs to the technical field of carbon fiber surface structure defect repairing, and in particular relates to a technique for repairing holes and cracks on the carbon fiber surface with a graphene film. Background technique [0002] Because carbon fiber has high axial strength and modulus, no creep, good fatigue resistance, specific heat and electrical conductivity between non-metal and metal, small thermal expansion coefficient, good corrosion resistance, low fiber density, X-ray Due to its good permeability and other advantages, it has been extensively studied as a reinforcement material for composite materials in the fields of aerospace, transportation, energy, sports, civil engineering, etc.; however, its active specific surface area is small and its surface energy is low. The bonding force between the matrix is ​​small, so that the shear strength and bending strength of the carbon fiber composite material are very low; moreover, th...

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Problems solved by technology

Cheng Bowen etc. adopt a method of electrostatically spraying carbon nanotubes to enhance the strength of carbon fibers in Chinese patent application numbers 201010211436.7, 201010211437.1, 201010122410.2, etc. The method is simple in process and the strength of carbon fibers is increased by 100%. However, due to the length range of carbon nanotubes in Between a few microns and tens of microns, which is much higher than the size of carbon fiber surface structure defects (about tens to hundreds of nanometers), thus restricting the entry of carbon nanotubes into carbon fiber surface structure defects during electrospraying (radial injection ) format, so that most of the carbon nanotubes are covered on the surface of the carbon fiber; in addition, due to the relatively large length of the carbon nanotubes, the carbon nanotubes are easy to entangle with each other during the electrostatic spraying process, which affects the spraying effect

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