Easily enlarged and coating-free underwater superoleophobic fabric for oil/water and emulsion separation via a facile NaClO2 treatment

Underwater superoleophobic membranes for oil/water separation have made great progress. Nevertheless, there are still some challenges in the simple fabrication of inexpensive and eco-friendly membranes with underwater superoleophobicity. Herein, a simple and effective approach was proposed to fabricate the fabric with super hydrophilic and underwater superoleophobic performance. The developed fabric can be used as a membrane for gravity driven separation of a series of oils from water both in gentle environment and harsh environments (highly acidic, alkaline, and salty solutions), exhibiting high separation efficiency ( > 95.7%) and good recyclability. More importantly, the treated fabric is capable of separating oil-in-water emulsions driven only by the gravity with high efficiency ( > 92.8%) and high flux (2184-4588 L m(-2) h(-1)). This study provides a simple strategy to fabricate underwater superoleophobic fabric for water purification and oily wastewater treatment.