▎ 摘　　要

NOVELTY - Surface oxidation treatment on pre-oxidized and carbonized carbon fiber bundle is carried out, and corona discharge is carried out under high voltage. Then, graphene suspension is prepared by uniformly mixing graphene and organic solvent, electrostatic deposition of graphene is carried out by applying the positive static electricity and planting graphene into the surface structure defects of the carbon fiber. Then, heat treatment is carried out on carbon fiber bundle under argon inert gas atmosphere, to improve tensile strength of the carbon fiber. USE - Method for improving tensile strength of carbon fiber (claimed). ADVANTAGE - The method enables improvement of tensile strength of the carbon fiber into more than 160%. DETAILED DESCRIPTION - Surface oxidation treatment on pre-oxidized and carbonized carbon fiber bundle is carried out, passed through high-voltage corona discharge area, and corona discharge is carried out under high voltage of -5 kV to -30 kV with speed of 5-30 m/hour, such that the surface of the carbon fiber is functionalized and certain amount of negative charge is taken along in the surface structure defects of the carbon fiber. Then, 10-60 g/L graphene suspension is prepared by uniformly mixing graphene and organic solvent. The electrostatic deposition of graphene is carried out by applying the positive static electricity of 20-50 kV to the graphene suspension, flattening charged carbon fiber bundle, forming suspension acceptor by grinding, planting graphene into the surface structure defects of the carbon fiber by virtue of electric atomization deposition and controlling the weight ratio of the carbon fiber to the graphene in deposit into 1000:0.1-4, and deposition distance of 5-30 cm. Then, heat treatment is carried out on carbon fiber bundle under argon inert gas atmosphere at 300-1600 degrees C after atomization deposition is carried out by virtue of the graphene, to improve tensile strength of the carbon fiber. The corona discharge device consists of high voltage power supply, cathode discharge device and ground electrode plate. The high voltage power supply is from negative high voltage power generator. The cathode discharge device is connected to ground electrode plate through a wire. The graphene is functionalized graphene derived from amino, sulfonated or hydroxylated graphene. The solvent is dimethyl acetamide, dimethyl formamide, tetrahydrofuran or ethanol, and contains 0.5-4 wt.% functional group. Electrostatic deposition device consists of high voltage power supply, multi-needle ejector pin and ground electrode plate. The high voltage power supply is from positive high voltage power generator. The high voltage power supply is connected with the anode through wires.