Fabrication of crosslinking modified PVDF/GO membrane with acid, alkali and salt resistance for efficient oil-water emulsion separation

Although a great deal of superhydrophilic/underwater superoleophobic membranes has been developing for oil-water emulsion separation, most of them could be destroyed or lose their underwater superoleophobicity after exposure to complex conditions. In this study, a crosslinking modified PVDF/GO membrane with acid, alkali and high salt resistance was successfully prepared by a simple crosslinking process between acrylic acid and ethylene glycol dimethacrylate (EGDMA). The influences of content of acrylic acid on the membrane performance and structure evolution were investigated. The resultant composite membrane showed superior underwater superoleophobicity even in acid, alkali and salt environments. Additionally, the composite membrane could effectively separate various surfactant-stabilize emulsions under gravity-driven via wettability capillary effect with high rejection (>99%) and flux (>145 L m⁻² h⁻¹). The composite membrane also exhibited outstanding recyclability because of the stable covalent bridged multiple networks structure. The antifouling performance, stability and impressive recyclability make the composite membrane a promising candidate for long-term oil-water emulsion treatment.