Smart superamphiphobic surface manipulating wetting behaviors of oil droplet in water

Under limited lubrication oil supply, wettability is closely related to the distribution of oil around the contact zone, which directly affects lubricating performance of mechanical surfaces. Up to now, manipulating oil wetting behaviors remains a challenge. Here superamphiphobic surfaces are prepared by grafting perfluoroalkyl chain on superhydrophobic Cu coating without any low-surface-energy modifier. Furthermore, the surface chemistry of the superamphiphobic surfaces is finely adjusted by introducing terminal carboxyl group. Under the appropriate surface energy, superoleophilicity and superoleophobicity of the superamphiphobic surface in water can be efficiently switched via simply adjusting water pH value. Utilization of intrinsic wetting properties of materials will provide a pathway to guide programmable friction characteristics of engineering materials with controllable oil wetting behaviors in multiphase media.