Controllable edge modification of multi-layer graphene for improved dispersion stability and high electrical conductivity

Effective edge modification of graphene with high structural integrity has been a challenging issue for fabricating high-performance nanocomposites with uniform dispersion, strong interfacial interaction, and multi-functional properties. In this work, we have developed a simple and controllable method to obtain edge-modified graphene with good dispersion stability and high electrical conductivity. Highly conductive multi-layer graphene were first used as precursors and mechanically smashed into small-size pieces, and subsequently the smashed graphene were selectively edge-modified in mild media due to the high edge reactivity. We have investigated the microstructure, chemical composition, oxidation degree, dispersion stability, and electrical conductivity of the edge-modified graphene in detail. It was found that the edge-modified graphene possessed satisfactory dispersion stability and high electrical conductivity, which is mainly attributed to high structural integrity of pristine graphene, effective edge modification, and controllable oxidation degrees. Such high dispersion stability and electrical conductivity can be well controlled by adjusting treatment conditions in a simple way. The edge-modified graphene exhibited great potential to be used as multi-functional nanofillers for fabrication of high-performance composites.