LAUSR

Abstract Excellent antifouling membrane surfaces and membrane cleaning efficiency are immensely desired but challenging to achieve. In this study, we initially prepared pH-responsive hydrophilic membrane surfaces by introducing carboxyl groups onto polyvinylidene fluoride (PVDF) membrane surfaces via amine group bridging. Then, partial perfluoroalkylation modification was performed through an amidation reaction between the carboxyl groups on the hydrophilic membrane surface and amine groups of fluorinated diamine. Therefore, a membrane surface with a discontinuous amphiphobic fluorine island structure was successfully fabricated. Experimental results for soybean oil/water emulsion separation demonstrated that compared with hydrophilic-modified membrane (PVDF–MAH), the stable flux of fluorine island-modified membrane (PVDF–PFOA) increased by approximately 67%. Moreover, compared with the PVDF–MAH membrane, the flux of the PVDF–PFOA membrane at the end of the fourth filtration cycle (i.e., before chemical cleaning) increased by approximately 34% and its flux recovery rate at the beginning of the fifth filtration cycle (i.e., after chemical cleaning) increased by approximately 6%. The as-prepared membrane with fluorine island structure facilitates a new effective method for solving the membrane fouling problem during practical applications of membrane technology.