Colorful Polymer Compositions with Dyed Graphene Oxide Nanosheets

Abstract

A water suspension of graphene oxide nanosheets (GONSs) obtained via exfoliation of a graphite oxide was treated with a solution of rhodamine 6G. It was found that adding the dye results in the destruction of the GONS water suspension and the precipitation of dyed graphene oxide. The precipitate, washed out of the excess dye and subjected to a second dispersal via sonification, provides a stable suspension of dyed GONS in water or dimethylformamide. The GONS dyeing produces shifts of major absorption bands of the dye in solutions or in polymer compositions toward larger wavelengths. We also found that the stability of a dye subjected to ultraviolet irradiation increases if the dye is bound to a GONS. The increased stability resulted from excitation transfer from dye to a GO nanosheet and its subsequent reduction.