Polyethersulfone membrane modified by zwitterionic groups for improving anti-fouling and antibacterial properties

Ultrafiltration (UF) membranes are commonly confronted with threats from pollutants during long-term operation. The zwitterions with high hydrophilicity are expected to be the critical material to improve the anti-fouling and antibacterial abilities of membranes. Herein, a new zwitterionic polyethersulfone (PES) (zwitterionic PES - ZPES) was synthesized. The as-prepared ZPES was used to fabricate a zwitterionic UF membrane via the non-solvent induced phase inversion (NIPS) method. Zwitterionic polymer skeleton enhanced the hydrophilicity, permeability and anti-fouling properties of the material. As a result, the ZPES membrane exhibited doubled water flux growth (269.6 L·m−2·h−1) compared with that of the PES (125.3 L·m−2·h−1) and high protein rejection (98.6%). Besides, the ZPES membrane could maintain an excellent flux recovery rate (94.1%) and antibacterial effect (more than 95%). Therefore, the excellent anti-fouling and antibacterial abilities of the ZPES membrane broaden its application scope further.