Preparation of poly(tetrafluoride ethylene-r-vinylpyrrolidone) modified PVDF membrane with comprehensive antifouling performance for efficient separation of challenging oil-in-water emulsions

摘要

In this work, we have designed and fabricated an ultrathin poly(tetrafluoride ethylene-r-vinylpyrrolidone) (F-VP) layer with controllable thickness of 2 urn, supported by commercial polyvinylidene difluoride (PVDF) substrate (hereafter named F-VP/PVDF membrane), via an extremely simple, scalable and one-step surface modification method. The F-VP/PVDF membrane showed an excellent superhydrophilic/under oil superhydrophilic properties, as well as superoleophobic property to various oils (soybean oil, hexadecane and hexane). The F-VP/PVDF membrane with tunable effective pore size of ～ 400 nm could efficiently separate various complex oil-in-water emulsions containing surfactants with high water permeability of 4612 L m~(-1) h~(-1) bar~(-1), high emulsion permeability of 745 L m~(-1) h~(-1) bar~(-1) (10000 ppm soybean oil-in-watcr emulsion) with a high rejection efficiency ratio of >99.9%, and an extremely fouling-rcsistant and fouling-releasing property of nearly 100% flux recovery over 5-time continuously cyclic tests.