Antifouling Oil–Water Separation Membrane: Achieving Efficient Demulsification and Surface Oil Contamination Removal through Enhanced Piezoelectric Properties

Stable oil–water emulsions containing micron-sized oil droplets readily foul conventional separation membranes, leading to severe pore blockage, rapid flux decline, and reduced operational stability. In this work, a piezoelectric nanofibrous membrane based on polarized PVDF/BaTiO 3 composite fibers was developed for enhanced emulsion separation and antifouling performance. The incorporation of tetragonal BaTiO 3 nanoparticles promoted β-phase formation in PVDF and improved the piezoelectric response of the membrane after polarization treatment. Compared with nonpolarized membranes, the polarized membrane exhibited improved flux stability and oil rejection performance during continuous oil–water emulsion separation. The enhanced separation behavior is correlated with the piezoelectric-assisted interfacial response generated during membrane operation. Under mechanical perturbation induced by fluid flow, localized piezoelectric polarization may contribute to reducing oil adhesion and suppressing fouling accumulation on the membrane surface. Although the precise interfacial mechanism requires further direct experimental verification, the observed improvement in antifouling behavior is consistent with previously reported piezoelectric interfacial effects. The optimized membrane achieved a separation efficiency above 99% together with stable long-term flux performance during continuous emulsion separation. This work demonstrates a feasible strategy for integrating piezoelectric functionality into nanofibrous membranes for antifouling oil–water separation.