Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Schematic illustration of zwitterionic AEA-S functionalized PVDF hollow fiber membranes via polydopamine-assisted coating, demonstrating enhanced antifouling and antibacterial performance.

ABSTRACT
The zwitterionic monomer quaternary ammonium aminoethylamine sulfonate (AEA-S) was synthesized via the quaternization reaction of tris(2-aminoethyl)amine and 1,3-propanesultone in ethanol. The antibacterial activity of AEA-S was evaluated using inhibition zone, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) tests, confirming its effective antimicrobial performance. A zwitterionic AEA-S/Polydopamine (PDA) layer was fabricated as a selective layer on the external surface of the polyvinylidene fluoride (PVDF) hollow fiber membrane substrate using a continuous flow-through coating technique. Surface modification significantly influenced membrane surface charge, morphology, roughness, hydrophilicity, water permeability, and antifouling behavior. The optimized zwitterionic ultrafiltration (UF) membrane (AEA-S/PDA-PVDF-3), prepared at a 1:1 M ratio of AEA-S to PDA with a total concentration of 1.84% (w/w), exhibited a pure water flux = 116.49 L m−2 h−1 and a bovine serum albumin (BSA) rejection of approximately 78.6% at an operating pressure of 1 bar. A PEO (200 kDa) rejection of 92.1% was obtained for molucular weight cut-off (MWCO) determination. The modified membrane also demonstrated a high BSA flux recovery ratio of 80.8% and reduced protein adhesion compared to the pristine PVDF hollow fiber membrane. The zwitterionic membrane exhibited high flux, enhanced hydrophilicity, and excellent antifouling and antibacterial performance.