Flexible film materials from conjugated dye-modified polymer surfactant-induced aqueous graphene dispersions

Abstract

A novel polymeric surfactant composed of a hydrophobic perylene dye covalently linked to hydrophilic poly(vinyl alcohol) (PVA) chains was employed to prepare stable aqueous dispersions of graphene. The presence of well-dispersed few layer graphene was demonstrated by UV-visible, Raman and fluorescence spectroscopy. This polymeric surfactant has an additional advantage in that it can be used to immobilize graphene within stable films that are transparent, flexible and easily processed. Indirect evidence of a strong interaction between perylene and graphene was obtained from the analysis of the physical properties of the polymer films. A complete loss of crystallinity and a remarkable reduction in segmental mobility manifested by an increase of around 50 °C in the glass transition temperature were observed. The imaginative molecular design of polymers covalently modified with planar aromatic molecules presents important opportunities in the development of new application possibilities of graphene.