A Facile Approach to Covalently Functionalized Graphene Nanosheet Hybrids and Polymer Nanocomposites

Abstract 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) nanosheet 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.