Janus Nanofiber Antibacterial Membrane for Switchable Separation of Oil/Water Emulsions

Treatment and recycling reuse of oily wastewater caused by offshore oil spill accidents and the discharge of food industry have become an urgent hot issue and promote the development of oil/water separation materials. However, the efficient separation of oily wastewater still remains a big challenge. Simple, low-cost, and easily scale-up processes for the fabrication of materials to effectively separate oil/water mixtures, especially stabilized emulsions, with high efficiency and that are durable in wastewater treatment are urgently desired. Herein, a scalable, low-cost, and antibacterial Janus AgNPs@PVA-co-PE (PVA, polyvinyl alcohol; PE, polyethylene) membrane was developed by spraying the hydrophilic PVA-co-PE nanofiber on both surfaces of the polypropylene substrate (denoted as PP) and then selectively decorating one side with hydrophobic fluorosilane. The obtained Janus PVA-co-PE membranes can effectively separate stabilized emulsions, including nonionic, cationic, and anionic types, and they display high separation efficiency (>99.9%) and promising flux solely driven by gravity. The synergistic effect between the bactericidal properties of Ag+ and antiadhesion of superhydrophobicity endows the AgNPs@PVA-co-PE membrane with a strong antibacterial activity against Escherichia coli and Staphylococcus aureus.