▎ 摘　　要

NOVELTY - Two-dimensional graphene-coated copper composite material has a core-shell structure, and nano-copper particles, which are wrapped by an outer layer of graphene to form a core-shell structure. The diameter of the nano-copper particles is 40-50nm, thickness of the shell layer is 3-5nm, which is prepared by preparing graphene oxide-water dispersion, and preparing surface-modified copper particles by dispersing pure copper powder uniformly in water, then adding 3-aminopropyltriethoxysilane and dispersing for 3-5 hours at 40-80 degrees C, and then obtaining a mixed suspension, sealing , incubating at 100-200 degrees C for 12-36 hours, collecting the precipitate and washing, to obtain surface-modified copper particles. USE - Two-dimensional graphene-coated copper composite material used in polyethylene oxide/graphene-coated copper nanocomposite material as filler for electromagnetic shielding (claimed). ADVANTAGE - The two-dimensional graphene-coated copper composite material has excellent electromagnetic shielding performance. DETAILED DESCRIPTION - Two-dimensional graphene-coated copper composite material has a core-shell structure, and nano-copper particles, which are wrapped by an outer layer of graphene to form a core-shell structure. The diameter of the nano-copper particles is 40-50nm, thickness of the shell layer is 3-5nm, which is prepared by preparing graphene oxide-water dispersion, and preparing surface-modified copper particles by dispersing pure copper powder uniformly in water, then adding 3-aminopropyltriethoxysilane and dispersing for 3-5 hours at 40-80 degrees C, and then obtaining a mixed suspension, sealing , incubating at 100-200 degrees C for 12-36 hours, collecting the precipitate and washing, to obtain surface-modified copper particles. The surface-modified copper particles obtained are added to the graphene oxide-water dispersion obtained in step 1 and dispersed uniformly, and then added and reduced at 40-80 degrees C Sodium hypophosphite is used, then solid product is separated, washed and dried to obtain graphene-coated copper nanocomposite, which is recorded as Cu@RGO. INDEPENDENT CLAIMS are included for the following: (1) polyethylene oxide/graphene-coated copper nanocomposite material, is used as a filler, and polyethylene oxide is used as a polymer, and substrate is obtained by a solution blending method to obtain a polyethylene oxide/graphene coated copper nanocomposite; and (2) method for preparing a two-dimensional graphene-coated copper composite material with a core-shell structure, involves obtaining a graphene oxide-water dispersion; obtaining surface-modified copper particles by dispersing pure copper powder uniformly in water, then adding 3-aminopropyltriethoxysilane and dispersing for 3-5 hours at 40-80 degrees C, and then obtaining a mixed suspension and sealing and incubating at 100-200 degrees C for 12-36 hours, collecting the precipitate and washing, to obtain surface-modified copper particles; obtaining graphene-coated copper nanocomposite involves adding to the graphene oxide-water dispersion and dispersing uniformly, and then adding and reduced at 40-80 degrees C and using sodium hypophosphite, then separating solid product, washing and drying to obtain graphene-coated copper nanocomposite, which is recorded as Cu@RGO.