An intelligent natural fibrous membrane anchored with ZnO for switchable oil/water separation and water purification

Materials with superwettability have attracted much research interest over the last few decades in the field of water-oil separation. Distinct from other superwetting materials, dual superlyophobic materials that have superoleophobicity in water and superhydrophobicity in oil can perform on-demand oil/water separation without requiring extra energy. However, obtaining such a dual superlyophobic membrane with multifunctionality for application in a complicated wastewater environment remains a challenge. Taking advantage of both ZnO and polydopamine, a multifunctional PDA/SC/KFs@ZnO freestanding membrane was prepared in our study. This novel material displays dual superlyophobicity and has potential application for rapid and simultaneous separation of light and heavy oil-water mixtures, oil-in-water emulsions with soluble dye, and water-inoil emulsions, as well as a good adsorption-catalysis performance for removing soluble dyes in water under visible light. Our work presents a facial and economic method that uses natural kapok fibers to fabricate a special multifunctional superwetting membrane that is promising for future applications.