Covalently intercalated graphene oxide for oil–water separation

We report the transformation of hydrophilic graphene oxide (GO) sheets into superhydrophobic nanomaterial by direct esterification with epoxy-functionalized polyhedral oligomeric silsesquioxane (ePOSS). The covalently functionalized GO–ePOSS composite shows superhydrophobicity with a water/air contact angle of ∼145°. The highest dispersion limits for GO in selected organic solvents are obtained in the literature. The dispersion of GO–ePOSS can be extended to solvents with Hansen solubility parameters as low as 3.4. Efficient oil–water separation is also demonstrated by using a GO–ePOSS membrane.