Robust, Antifouling, and Hydrophilic Particle-Based Double-Network Hydrogel–PVDF Interpenetrating Microfiltration Membrane

Poly(vinylidene fluoride) (PVDF) membranes with highly hydrophilic and antifouling properties are desirable for oily wastewater treatment. Herein, we report (1) a strategy of bulk modification of PVDF by in situ integration of PVDF and a particle-based double-network (PDN) hydrogel, poly-2-acrylamido-2-methylpropanesulfonate/polyacrylamide (PAMPS/PAAm), via a strong PDN and PVDF interpenetrating polymer network (PDN–PVDF IPN) to obtain a PVDF/PDN solution and (2) the subsequent casting of it into a microfiltration membrane via spray-assisted non-solvent-induced phase separation (SANIPS). The IPN structure modulates the surface segregation behavior of the highly hydrophilic and robust PDN hydrogel in the process of SANIPS, endowing the resulting PVDF/PDN membrane with excellent bulk mechanical properties and much enhanced wettability and thereby high oil/water emulsion separation efficiency and antifouling performance. Moreover, the PVDF/PDN membrane presented good chemical stability upon soaking in strongly acidic and alkaline solutions for an extensive time. Our work expands the research in phase-inversion-based antifouling oil/water separation materials.