Fabrication of Polytetrafluoroethylene Composite Membrane via Laser Perforating and Nanosilica Coating for Efficient Oil–Water Separation

ABSTRACT Oil/water separation membrane has attracted increasing attention due to the environmental issue caused by industrial oily wastewater and frequent oil spill incidents. Techniques for preparation of high‐performance membranes are still in need of advancing. In this work, an environment‐friendly polytetrafluoroethylene composite membrane was fabricated with a two‐step method, i.e., picosecond laser perforating and subsequent nano‐silica composite coating. The in‐air water contact angle of the prepared membrane was 0°, and the underwater oil contact angle was over 150°, showing excellent superhydrophilic/underwater superoleophobic properties and self‐cleaning performance. Results also showed that an average separation efficiency above 96% was obtained for the composite membrane for a variety of oil–water mixtures. The tailored wettability and separation efficiency remained after abrasion and corrosion tests, indicating good durability of the membrane in harsh environment.