NH₂-CAU-1 modified polyphenylene sulfone (PPSU) membrane for separation of oil-in-water emulsions

The wettability of the membrane surface is very important for the separation of oil-in-water emulsion. In this paper, the hydrophilic NH₂-CAU-1 was added to the membrane surface by interfacial polymerization, which greatly improved the separation efficiency of oil-in-water emulsion. The effect of the amount of NH₂-CAU-1 on the separation efficiency of TFN membrane was studied, and it was determined that TFN-1 membrane had ultra-high separation efficiency of oil-in-water emulsion (> 97.60%). TFN-1 membrane has a high underwater oil contact angle (higher than 139.53°), resulting in excellent oil adhesion resistance on the membrane surface. The universality and cycling performance of TFN-1 membrane were tested, and UWOCA had good stability under strong acid, strong base and different NaCl concentrations, and the separation efficiency did not change significantly after 8 cycles. The results show that TFN-1 membrane has excellent performance in separating oil-in-water emulsions and has broad application prospects in separating oil-in-water emulsions stabilized by surfactants.