Piezoelectric Separation Membranes via Dual‐Side Polarization for Micro‐Powered and Fluid‐Responsive Functions

ABSTRACT

Membrane fouling remains a major limitation for the long‐term operation of pressure‐driven separation processes. Although piezoelectric membranes provide a promising route for self‐powered antifouling, it is still challenging to fabricate porous membranes that combine high permeability with high electroactive β‐phase content through scalable processes. Here, we report a dual‐side synergistic polarization strategy based on a modified non‐solvent induced phase separation process, in which the NMP solvent and sodium alginate coagulation bath cooperatively promote PVDF chain rearrangement during membrane formation. This approach yields PVDF/PDA@UiO‐66‐NH ₂ (Hf) composite membranes with enhanced β‐phase content and piezoelectric response. Under pulsed hydraulic pressure, the membrane converts fluid fluctuations into in situ piezoelectric potential, which contributes to pollutant repulsion and reactive oxygen species generation for self‐cleaning. The optimized membrane exhibits a flux of 1655 L·m ⁻² ·h ⁻¹ ·bar ⁻¹ and a rejection above 99% during emulsion separation, while the flux decline rate is reduced to 8.67%, compared with 33.10% under constant‐pressure operation. This work provides a feasible route for constructing piezoelectric PVDF separation membranes and offers insight into coupling dynamic antifouling with emulsion separation in a single membrane platform.