Water/oil repellency and work of adhesion of liquid droplets on graphene oxide and graphene surfaces

► The study examines the water/oil repellency of graphene and graphene oxide sheets. ► The graphene nanosheets were produced by reducing graphene oxide. ► A modified Young-Duprè equation, incorporated with the Cassie parameter, was used. ► Porous graphene sheets offer an air cushion to repel the drop penetration. ► The existing air layer induces the movement of the sliding drop.