Robust PVA-GO-TiO2 composite membrane for efficient separation oil-in-water emulsions with stable high flux

Most super-wetting membrane materials are susceptible to oil pollution after separation process, causing a serious degradation of the separation ability. The rough structure of underwater superoleophobic membrane can effectively improve anti-fouling property, thus achieving stable separation. Herein, a composite polyvinyl alcohol-graphene oxide-titanium dioxide (PVA-GO-TiO2, PGT) membrane with rough structure is prepared through a simple hydrothermal and suction-filtration method. The as-prepared PGT membrane displays outstanding underwater superoleophobicity even for high-adhesion crude oil. Moreover, the as-fabricated membrane exhibits efficient oil-in-water emulsions separation performance with separation efficiency of larger than 99.1% and permeation flux of over than 762 L m−2 h−1 even after 10 min. Besides, the PGT membrane could separate various oil-in-water emulsions in corrosive environments with separation efficiency of higher than 99.3% and permeation flux of more than 760 L m−2 h−1. More importantly, the as-prepared membrane could keep the underwater superoleophobicity after sanding test (200 times) and bending test (500 times). The composite membrane with excellent oil-in-water emulsions separation performance, corrosion resistance and mechanical stability has broad prospects in the field of water purification.