A Facile and Fast Approach To Coat Various Substrates with Poly(styrene-co-maleic anhydride) and Polyethyleneimine for Oil/Water Separation

Poly­(styrene-co-maleic anhydride) (PSMA) and polyethyleneimine (PEI) are used to coat various substrates via a facile and fast process to improve their oil/water separation performances. Substrates including polyvinylidene fluoride (PVDF) microfilter membrane, cotton fabric, nylon mesh, and stainless steel mesh are initially coated with PSMA and subsequently with PEI to yield cross-linked copolymer coatings. The coating procedure can be finished in 30 min. Notably, the copolymer coating can endow the substrate with superhydrophilic and underwater superoleophobic properties, as well as dynamic underwater anti-oil-fouling performance. The successful coating of cross-linked copolymers onto the substrate surface was verified by SEM, ATR-FTIR, and XPS characterization. All of the coated substrates can be used for the separation of the oil/water mixture, and the coated PVDF microfilter membrane offers excellent oil/water emulsion separation performance. More importantly, the coatings can withstand exposure to acidic and basic media as well as repeated and long-term usage.