▎ 摘　　要

NOVELTY - Preparing three-dimensional network connecting graphene-based composite heat interface material comprises peeling the poly (p-phenylene benzobisoxazole) fiber (PBOMF), obtaining poly (PBONF) solution with different concentrations of poly (p-phenylene benzobisoxazole), taking the poly (PBONF) solution with low concentration as A solution, taking the PBONF solution with high concentration of poly (pphenylene benzobisoxazole) as B solution; dispersing the graphene nano sheet (GNS) in the A solution, obtaining the mixture acidic solution; adding strong electrolyte to the mixture acidic solution, forming GNS-PBONF sol of three-dimensional network connection frame; forming the GNS-PBONF adhesive sol of compact three-dimensional network structure; incubating adhesive sol to form acidic gel, soaking acidic gel in the deionized water, using acid and water exchange to remove the acid in the gel, obtaining hydrogel; and drying the hydrogel. USE - Preparing three-dimensional network connecting graphene-based composite heat interface material used in electronic device e.g. terminal device and communication base station. ADVANTAGE - The method solves the dispersion graphene the polymer, and greatly improves the filling amount of the graphene, and prepares the heat interface material with excellent heat-conducting performance. The method uses low concentration A solution to disperse graphene nano sheet (GNS), which not only makes the GNS disperse more uniform, and PBONF nano-wire and GNS nano-sheet pre-build three-dimensional network frame structure, which can prevent GNS reunion, with high stability. Good for subsequent high concentration B solution filling GNS-PBONF three- dimensional network is more compact and firm, and the porosity is uniform. DETAILED DESCRIPTION - Preparing three-dimensional network connecting graphene-based composite heat interface material comprises (S1) peeling the poly (p-phenylene benzobisoxazole) fiber (PBOMF), obtaining poly (PBONF) solution with different concentrations of poly (p-phenylene benzobisoxazole), taking the poly (PBONF) solution with low concentration as A solution, taking the PBONF solution with high concentration of poly (pphenylene benzobisoxazole) as B solution; (S2) dispersing the graphene nano sheet (GNS) in the A solution, obtaining the mixture acidic solution; (S3) adding strong electrolyte to the mixture acidic solution, forming GNS-PBONF sol of three-dimensional network connection frame; (S4) mixing B solution in the GNS-PBONF sol of the three-dimensional network connection frame, forming the GNS-PBONF adhesive sol of compact three-dimensional network structure; (S5) incubating GNS-PBONF adhesive sol of the threedimensional network structure to form acidic gel, soaking the acidic gel in the deionized water, using acid and water exchange to remove the acid in the gel, obtaining hydrogel; and (S6) drying the hydrogel, obtaining the GNS-PBONF thermal interface material connected by three-dimensional network. An INDEPENDENT CLAIM is also included for a three-dimensional network connecting graphene-based composite heat interface material, comprising a graphene nano sheet and polyparaphenylene benzobisoxazole nano-fiber, where the polyparaphenylene benzobisoxazole nano fiber is inserted between the multi-layer sheet graphene sheet, the sheet graphene sheet and the polyparaphenylene benzobisoxazole nano fiber form a threedimensional network structure; the mass ratio of the graphene sheet and the polyparaphenylene benzobisoxazole nano fiber is 40/60 to 70/30; the thermal conductivity of the threedimensional network connected with the graphenebased composite thermal interface material is 47- 93 W/m K.