Alkaline-induced superhydrophilic/underwater superoleophobic polyacrylonitrile membranes with ultralow oil-adhesion for high-efficient oil/water separation

Abstract Traditional polymer membranes prepared by phase inversion process have the problems of low flux and serious fouling when they were used for oil/water separation. In this work, an alkaline-induced phase inversion process is developed for the superhydrophilic/underwater superoleophobic polyacrylonitrile (PAN) ultrafiltration membrane. The as-prepared PAN ultrafiltration membrane could effectively separate oil-in-H2O emulsions with a high flux up to 2270 L/m2 h bar and an extremely high rejection while the oil residual in filtrate after one-time separation is lower than 10 ppm. Also, the PAN membrane showed ultralow oil adhesion and antifouling properties and can be easily recycled with flux recovery ratio of 85%. This new PAN membrane has a great potential for treating oily wastewater.