pH-Responsive Multifunctional Materials with Switchable Superamphiphobicity and Superoleophobicity-Superhydrophilicity for Controllable Oil/Water Separation

Stimulus-responsive materials with controllable oil/water separation performance have prodigious potential application. Here, a new thought for low-cost, time-saving, flexible approach has been developed to prepare a pH-responsive material with switchable superamphiphobicity and superoleophobicity-superhydrophilicity. The as-prepared material can be easily applied onto multifarious substrates and presents stable superamphiphobicity. However, when the modified material is treated by alkaline solution, its surface wettability turns superhydrophilicity and superoleophobicity, thus water is allowed to penetrate through the material whereas the oil was blocked on the surface. Moreover, the surface wettability can be recovered to superamphiphobicity quickly via treating the material with acidic aqueous. Hence, such a controllable water wettability and stable oil repellency property endows the as-prepared material with excellent capability to separate water from oil/water mixture. In addition, the pH-responsive materials can maintain switchable wettability after being treated by acid and alkali numerous cycles. Furthermore, the obtained materials also exhibit excellent recyclable, self-cleaning and flame-resistant performance, which shows potential applications for smart water-oil separators and fire-shielding protectors.