▎ 摘　　要

Homogeneous dispersion and a good interface between polymer and filler is crucial to obtain high-performance polymer composites. In this work, we use a novel method employing organic aminopropyl-functionalized nanosilica sols (OAS-sols) to functionalize graphene oxide (GO) and thereby synthesize OAS covalently grafted graphene hybrid nanosheets (OAS-graphene). The spherical OAS covalently attached on the two-dimensional (2D) nano-sheet GO surfaces creates OAS-graphene hybrids, which have large surface areas and homogeneous amino active sites distributed on the nanosheets. The OAS-graphene gave an improved dispersion and interface compatibility as well as a decreased thermal interfacial resistance. As a result, the thermal conductivity and mechanical properties of the epoxy nanocomposites were significantly improved at low loading while maintaining high electrical insulative properties.