Polyamine-functionalized perylene bisimide for dispersion of graphene in water with high effectiveness and little impact on electrical conductivity

Dispersion of graphene with high effectiveness is a great challenging task. In this paper, a series of water-soluble polyamine-functionalized perylene bisimide derivatives (HAPBI) were synthesized and further used as the stabilizer of graphene in water. It was found that the number of amine group strongly determined the water solubility of HAPBI and its effectiveness on stabilizing graphene. With triethylenetetramine-functionalized perylene bisimide (HAPBI-3), high concentration of aqueous graphene dispersion up to 1.0 mg mL⁻¹ was obtained at the weight ratio of HAPBI-3 to graphene even down to 1:3, demonstrating its higher efficiency to the common surfactants, polymer, and other perylene bisimide derivatives reported. Moreover, graphene's electrical conductivity is less impacted compared with polyvinylpyrrolidone (PVP), particularly favoring for its further application. Careful inspection indicated that HAPBI-3 molecules strongly interacted with graphene in a process of de-assembly of their self-aggregates and subsequently irreversible restacking on graphene sheets.