CO2-Induced Reversible Dispersion of Graphene by a Melamine Derivative

Smart graphene with stimuli-responsive dispersity has great potential for applications in medical and biochemical fields. Nevertheless, reversible dispersion/aggregation of graphene in water with biocompatible and removable trigger still represents a crucial challenge. Here, we report CO2-induced reversible graphene dispersion by noncovalent functionalization of reduced graphene oxide with N(2),N(4),N(6)-tris(3-(dimethylamino)propyl)-1,3,5-triazine-2,4,6-triamine (MET). It was demonstrated that MET can be strongly adsorbed on graphene surface through van der Waals interaction to facilitate dispersing graphene in water. Moreover, reversible aggregation/dispersion of graphene can be achieved simply by alternately bubbling CO2 and N2 to control the desorption/adsorption of MET on graphene surface.