Preparation of graphene-coated conductive fibers by layer-by-layer assembly of negative and positive charged graphene oxide

Abstract

Abstract Graphene recently gained extensive interests in electroconductive fibers because of its excellent electrical conductivity. Generally, graphene coated conductive fibers are fabricated in two steps, first graphene oxide (GO) dip-coated to the surface of the fiber, then GO reduced to reduced graphene oxide (RGO). To enhance the conductivity of the above fiber, the mass of graphene on the fiber surface is increased by repeated dip-coating of GO or alternating coating of GO and adhesive layer. The former method results in a low adsorption efficiency due to the electrostatic repulsion of graphene oxide. In the latter method, the adhesive layer is generally non-conductive, which reduces the electrical conductivity of the fiber. Thus we propose a novel method to prepare graphene coated conductive fibers by layer by layer assembly of the negative and positive charged GO dispersion here. In this study, the charge of GO was reversed to positive with AlCl3. Polyacrylonitrile (PAN) fiber was coated with Bovine serum albumin (BSA) to pretreat its surface. The pretreated PAN was then alternately dip-coated in the negative and positive GO dispersion. Finally, GO was reduced to graphene by the HI reagent. The prepared PAN conductive fiber has a resistivity of 38.5 Ω·cm, which is reduced by 7 orders of magnitude compared with the resistivity of the original PAN fiber. Moreover, the conductivity of graphene-coated fiber is maintained at around 92% after 10 washing treatments, demonstrating a better durability.