General route to graphene with liquid-like behavior by non-covalent modification

A graphene material with liquid-like behavior has been synthesized by decorating graphene in a generic, non-covalent fashion and subsequently combining the modified material with bulky polymer chains. The independently dispersed graphene core was first prepared through the chemical reduction of graphene oxide using a fluorescent whitening agent, VBL, as a non-covalent modifier. The negative groups of VBL, which are anchored onto the graphene sheets, impart anionic characteristics to graphene. The combination of the modified graphene with bulky Jeffamine M2070 chains through an electrostatic interaction yields a homogeneous graphene fluid, i.e., graphene-based nanoparticle ionic materials (G-NIMs). The microstructures of G-NIMs were characterized. G-NIMs can be stably dispersed in a broad spectrum of solvents with a super-high concentration of 500 mg mL^-1. The intriguing properties of the graphene core and fluidity properties of G-NIMs may offer new scientific and technological opportunities for the applications of graphene.