▎ 摘　　要

NOVELTY - Preparation of graphene dispersion involves dispersing a graphene oxide powder in a solvent (a1), preparing a graphene oxide aqueous dispersion, removing solvent (a1), mixing a solvent (a2) with the graphene oxide aqueous dispersion, reducing the graphene oxide aqueous dispersion, and purifying the reduced graphene oxide aqueous dispersion. USE - Preparation of graphene dispersion used for preparing graphene-polymer composite for producing barrier film (all claimed). Can also be used for forming nanomaterial, ink, thermal radiation material, and transparent electrode material. ADVANTAGE - The method enables preparation of graphene dispersion with excellent dispersibility of graphene, providing barrier film with excellent oxygen-barrier property and optical permeability. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) preparation of graphene-polymer composite, which involves dissolving a polymer resin in a solvent (a3), preparing a polymer resin solution, mixing the polymer resin solution and the graphene dispersion, preparing a mixed solution, and dispersing the mixed solution; and (2) production of barrier film, which involves coating the graphene-polymer composite on a base film, and drying.