Method for improving tensile strength of carbon fiber by utilizing graphene

Abstract

The invention relates to a method for improving tensile strength of a carbon fiber by utilizing graphene. An improved electric atomization deposition method is adopted for planting graphene into surface structure defects of the carbon fiber, so as to improve the strength of the carbon fiber. The method provided by the invention comprises the following steps of: 1) transmitting a pre-oxidized and carbonized carbon fiber bundle into a high-voltage corona discharge area, carrying out corona discharge under high voltage of minus 5kV to minus 30kV, wherein the advancing speed is 5-30m / h, so that a certain amount of negative charge is taken along in the surface structure defects of the carbon fiber; 2) preparing graphene, distilled water and small amount of dispersing agent into uniform and stable suspension, wherein functional graphene selected from amination graphene, sulfonation graphene and hydroxylation graphene is adopted, and the dispersing agent is one of imidazole benzene sulfonate ionic liquids; 3) applying positive static electricity of 20-50kV to the graphene suspension, flattening the charged carbon fiber bundle and grounding to form a spraying fluid acceptor, and then planting the graphene into the surface structure defects of the carbon fiber by virtue of electric atomization deposition, wherein deposit is controlled to be 1000:(0.1-4) in weight ratio of the carbon fiber to the graphene; and 4) carrying out heat treatment on the carbon fiber bundle under the insert gas argon atmosphere at the temperature of 300-1600 DEG C after atomization deposition is carried out by virtue of the graphene. The tensile strength of the carbon fiber can be improved by more than 130%.

Description

technical field [0001] The invention relates to a method for improving the tensile strength of carbon fibers by graphene, in particular to a method for repairing structural defects on the surface of carbon fibers with graphene by an improved electrospray deposition method, thereby improving the tensile strength of carbon fibers. Background technique [0002] Carbon fiber can almost be considered as the non-metallic material with the highest specific strength and specific modulus so far. In addition to excellent mechanical properties, it also has many other excellent properties, such as low density, high temperature resistance, chemical corrosion resistance, low electrical resistance, High thermal conductivity, low thermal expansion, radiation resistance, etc. have become indispensable reinforcement materials for advanced composite materials in the aerospace field, and have broad application prospects in transportation, energy, sports equipment, civil engineering and other fie...

AI Technical Summary

Problems solved by technology

However, the disadvantage of this technology is that the scale of carbon nanotubes is relatively large. Although its diameter is several to tens of nanometers, its length ranges from several microns to tens of microns, which is much higher than the size of carbon fiber surface structure defects (approximately several tens of nanometers). Ten to hundreds of nanometers), it is easy to cause only part of the carbon nanotubes to enter the surface structure defects of the carbon fibers during the electrostatic spraying process (radial injection), and most of the carbon nanotubes cover the surface of the carbon fibers; in addition, due to The length-to-diameter ratio of carbon nanotubes is large. During the electrostatic spraying process, carbon nanotubes will entangle with each other and form clusters, which will affect the spraying effect.

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