Fabrication of Electroconductive PVDF Membranes: Hierarchical Architectures for Synergistic Biofouling Suppression and Electrochemical Regeneration

Biofouling increases operational costs and downtime, significantly reducing membrane life and posing a persistent challenge for membrane installations. This work demonstrates a hierarchically designed electroconductive membrane for in situ electrochemical cleaning of biofouling. This composite membrane, made from a poly(vinylidene fluoride) polymer via the nonsolvent-induced phase separation (NIPS) method, reduces biomass adhesion by 85% and promotes effective regeneration via electricity-driven cleaning. Incorporation of laser-induced graphene (LIG) into the polymer matrix provides sufficient surface roughness to inhibit biofilm formation and induce electrochemical activity. The membrane, while maintaining a high rejection of up to 95% for PEG 400, achieved a high pure water permeability of ∼400 LMH bar^-1 with a molecular weight cut-off of ∼450 kDa. Various characterization techniques, including SEM, FTIR, Raman spectroscopy, and XPS, confirmed the formation of ultrafiltration membranes. Applying a 3 V cathodic potential during cross-flow regeneration achieved a flux recovery of ∼100%, outperforming cross-flow cleaning under identical conditions. The fabricated composite membranes also demonstrated mechanical stability, breaking at a stress of 26.23 MPa and a total membrane resistance of ∼9.6 × 10¹² (m^-1). The present study illustrates advancements in electricity-assisted self-cleaning membranes and their enhanced suitability in various treatment environments. These membranes will address the critical need for efficient water treatment solutions, reducing energy and chemical use while minimizing downtime.