Preparation and Performance of Anti-fouling Polyacrylonitrile Ultrafiltration Membranes
Polyacrylonitrile (PAN) ultrafiltration membranes are widely used in water treatment, yet their anti-fouling performance remains a challenge. In this work, PAN was first reacted with sodium azide via click chemistry to synthesize 1,2,3,4-tetrazolium polyacrylonitrile (PAN-N). Subsequently, PAN-N was reacted with iodoacetamide (IAM), 2-iodoethanol (IH), iodoacetic acid (IA), and chlorosulfonic acid (CSA) to introduce hydrophilic groups, and anti-fouling PAN ultrafiltration membranes were fabricated via phase inversion. The membranes were characterized by Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance, X-ray diffraction, scanning electron microscopy, and contact angle measurements. Results showed that the PAN-N membrane exhibited superior performance to pristine PAN, with water flux increasing from 0.9233 to 1.232 L·(m2·h·kPa)−1 and bovine serum albumin (BSA) rejection from 69.23% to 82.4%. Hydrophilic modification further enhanced performance; the PAN-N-IA membrane achieved the highest water flux of 1.7347 L·(m2·h·kPa)−1 and rejection of 93.57%. Anti-fouling tests revealed that modified membranes followed the order: PAN-N-CSA > PAN-N-IA > PAN-N-IH > PAN-N-IAM > PAN-N > PAN. PAN-N-CSA and PAN-N-IA showed comparable anti-fouling performance, with total fouling indices of 56.1% and 58.47%, reversible fouling indices of 47.17% and 46.97%, and irreversible fouling indices of 8.97% and 11.47%, respectively. This work demonstrates that PAN-N-IA membranes combine high flux, high rejection, and excellent anti-fouling properties, making them promising for water treatment applications.