Facile development of poly(tetrafluoride ethylene-r-vinylpyrrolidone) modified PVDF membrane with comprehensive antifouling property for highly-efficient challenging oil-in-water emulsions separation

Abstract Fouling problems caused by oil and other pollutants is one of the most severe challenges for membranes used for purification of comprehensive oil-in-water emulsions. Poly(tetrafluoride- r -vinylpyrrolidone) (F-VP) with low-adhesive superoleophobicity is a class of novel material for fouling-repellent membrane modification to achieve highly-efficient separation of complex oily wastewater. In this work, the construction of an ultrathin F-VP layer with a controllable thickness of 2 μm supported by polyvinylidene difluoride (PVDF) substrate was achieved, via an extremely simple, scalable and one-step surface modification process. Benefiting from the ultrathin modification F-VP layer, the resultant F-VP/PVDF membrane exhibited a superior comprehensive fouling-resistant and fouling releasing property, while maintaining a high mass-transfer efficiency without significant permeance sacrificing. The intrinsically non-fouling nature of F-VP modification layer endowed the F-VP/PVDF membrane with superoleophobic property to various oils, superhydrophilic/under oil superhydrophilic properties, and excellent antifouling property for comprehensive oil-in-water emulsions. The F-VP/PVDF membrane has high water permeance of 4612 L m −1  h −1 bar −1 , and high emulsion permeance of 461 L m −1  h −1 bar −1 (10000 ppm soybean oil-in-water emulsion) with high rejection ratio of >99.9%, and an outstanding, stable fouling-resistant and fouling-releasing property of ∼93% flux recovery over 5-time continuous cyclic tests. Overall, this work provides an insight into a facile preparation of advanced composite membrane with ultralow fouling-propensity property, which shows great potential in treating practically challenging emulsified wastewater.