• • Click chemistry conversion of PAN to PAN-N increased water flux from 0.9233 to 1.232 L·(m2·h·kPa)−1 and BSA rejection from 69.23% to 82.4%, demonstrating that tetrazole functionalization enhances membrane hydrophilicity and separation performance.
• • Hydrophilic modification with iodoacetic acid (PAN-N-IA) achieved the highest water flux of 1.7347 L·(m2·h·kPa)−1 and BSA rejection of 93.57%, representing a 88% increase in flux and 35% increase in rejection over pristine PAN, critical for high-efficiency water treatment.
• • Anti-fouling performance followed the order PAN-N-CSA > PAN-N-IA > PAN-N-IH > PAN-N-IAM > PAN-N > PAN, with PAN-N-CSA and PAN-N-IA showing total fouling indices of 56.1% and 58.47%, respectively, and irreversible fouling indices below 11.5%, indicating superior fouling resistance and extended membrane lifespan.
• • The introduction of hydrophilic groups (carboxyl, sulfonic, hydroxyl, amide) via covalent grafting promotes a hydration layer on the membrane surface, effectively reducing protein adhesion and fouling, which is essential for reducing operational costs in industrial water treatment.