Controllable preparation of multiple superantiwetting surfaces: From dual to quadruple superlyophobicity

Superantiwettability has been developed from single to multiple extreme wetting states for one wetting phase under another medium phase among water, oil, and air. However, controllable preparation of multiple superantiwetting surfaces especially from dual to quadruple superlyophobicity is rare. Herein, a facile method is proposed to prepare (1) underwater superoleophobic and underoil superhydrophobic surface, (2) in-air superhydrophobic surface with the dual superlyophobicity in oil-water system, and (3) in-air superamphiphobic surface with the dual superlyophobicity in oil-water system. These multiple superantiwetting states from dual to quadruple superlyophobicity are realized by controlling the surface chemistry, i.e., simply adjusting the ratio of TiO₂ nanoparticles and fluorocarbon surfactant in the spray solution. With minimum dosage of the fluorine-rich component, the dual superlyophobic surface can be used for on-demand oil-water separation. This discovery will promote the subdivision of superantiwettability in water-oil-air system to extend interfacial applications.