Flow-directed alignment enabling self-polarization and superior anti-fouling in PVDF piezoelectric hollow fiber membranes

Conventional high-voltage poling hinders the scalable production of piezoelectric hollow-fiber membranes (Pi-HFMs) due to its incompatibility with continuous wet-spinning. Here, a shear-flow-templating strategy is reported that enables one-step self-poling of PVDF hollow fiber membranes via alignment of platelet-like BaTiO 3 fillers during dry-jet wet-spinning. The aligned fillers not only elevate the electroactive β-phase content to 92.45%, but also template macroscopic dipole orientation, yielding an open-circuit voltage of 16 V without any external poling—comparable to conventionally poled membranes. The self-poled membranes exhibit superior antifouling performance against charged organics, organic-inorganic composites, and multi-component mixtures. Using particles with contrasting dielectric constants (SiO 2 , ε ~ 3.9 vs. BaTiO 3 , ε ~ 1000), the antifouling mechanism maybe originates from the negative dielectrophoretic (nDEP) effect. This work provides a scalable fabrication route for self-poled piezoelectric hollow fiber membranes and demonstrates a physical antifouling mechanism based on intrinsic dielectric properties, offering a robust and energy-efficient approach for membrane fouling control in water treatment.