Zwitterionic Quaternary Ammonium Aminoethylamine Sulfonate Functionalized Polyvinylidene Fluoride Hollow Fiber Membranes via Polydopamine‐Assisted Coating for Improved 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.