Preparation of light-sensitive polymer/graphene composite via molecular recognition by β-cyclodextrin

The dispersion of graphene in water has generally been considered an insurmountable challenge owing to its hydrophobic nature. In this study, a new type of light-sensitive polymer/graphene composite (AzoPEO/β-CD–RGO) was synthesized by the reversible host–guest interaction between azobenzene-terminal poly(ethylene oxide) (AzoPEO) and a β-cyclodextrin (β-CD) host attached to the surface of graphene via hydrogen bonding. In water, the AzoPEO/β-CD–RGO composite not only is well dispersed, but also exhibits reversible dispersion/aggregation behavior triggered by UV and visible light. Moreover, the graphene composite can be used to fabricate a light-responsive graphene-based drug delivery system. This kind of light-responsive graphene composite, which efficiently allows the control of graphene dispersion/aggregation, may find wide applications in the preparation of intelligent drug delivery systems, smart sensors, and switching devices.