UV-Cured Fluoride-Free Polyurethane Functionalized Textile with pH-Induced Switchable Superhydrophobicity and Underwater Superoleophobicity for Controllable Oil/Water Separation

Design and fabrication of smart surfaces for separation of oily water have been developed rapidly. Nevertheless, construction of these smart surface materials by using green and sustainable paths for intelligent separation of oily water still faces huge challenges. The aim of this study was to develop a facile, sustainable, and energy-efficient approach for the fabrication of smart coatings with pH-responsive switchable wettability. The coating was formed on the textiles from UV-cured fluoride-free pH-responsive polyurethane (pH-PU). The wettability of obtained textiles could switch reversibly between superhydrophobicity and underwater superoleophobicity due to the protonation and deprotonation of the pH-PU under different pH conditions, which was used to successfully separate either oil or water from oily water with high separation efficiencies. More importantly, oil-in-water and water-in-oil emulsions could all be selectively separated with high water flux and oil purity by as-fabricated textiles, and t...