Preparation of underwater superoleophobic polyimide mesh for oil/water separation via a simple Ce/Cu-MOF in-situ growth strategy

Abstract Superhydrophilic/underwater superoleophobic material has become ideal material for oily wastewater treatment due to its selectable wettability and anti-oil ability, but its large-scale application is limited by the harsh application environment. In this study, we reported a flexible dip-coating/in-situ growth strategy to synthesis superhydrophilic/underwater superoleophobic polyimide mesh (PM) for oil/water separation, including oil-water separation in corrosive chemical environments. As expected, the underwater oil contact angle (OCA) of the modified PM is above 153°, showing excellent underwater superoleophobicity. In addition, the coated PM still possesses underwater oleophobicity in corrosive solvents, extreme temperature and after suffering from scratching tests, expounding the stability of the functional PM. The separation efficiency of the modified PM for the oil/water mixture is above 98.5%. Even after fifty times of oil/water separation, the separation efficiency is still about 98%, which shows the good circulation separation behavior of the synthesized PM. Moreover, the separation efficiencies of coated PM for oil/physicochemical solution mixtures are ~99%, demonstrating a robust and stable oil/water separation function in corrosive environments.