▎ 摘　　要

NOVELTY - Graphene fiber comprises a graphene film formed into an elongated fiber-like shape and having imide groups formed on at least an outer surface of the graphene film. USE - The graphene fiber is useful for increasing strength of a composite material. ADVANTAGE - The graphene fiber improves the mechanical and electrical properties. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) a composite material comprising the graphene fiber and a matrix material; and (2) increasing strength of a composite material, comprising forming a graphene fiber comprising a graphene film formed into an elongated fiber-like shape and having imide groups formed on at least an outer surface of the graphene film, combining a resin matrix material with many the graphene fibers to form a prepreg material, and curing the prepreg material to form the composite material.