Synergistically enhancing the antibacterial and antibiofilm activities of anion exchange membrane by chemically assembling gentamicin and N-chloramine layers

Biofouling is one of significant obstacles decaying the high separation performance and long-term stability of polymer membranes during the application. To explore the desirable anti-biofouling anion exchange membrane (AEM), in this work, a series of modified AEMs having surface antibacterial functional layers on surface has been prepared by using gentamicin and N-chloramine for electrodialysis (ED). The antibacterial functional layer on surface was constructed via chemical assembly. By using CuSO 4 and H 2 O 2 as the trigger, l -dopa was oxidized on surface of commercial AEM (Fuji type II) to form a carboxyl layer. Thereafter, gentamicin was chemically assembled via the amide condensation reaction . It was chlorinated with diluted NaClO solution to endow it with synergistic antibacterial activity by using gentamicin. Investigation demonstrates that the optimized membrane of P( l -Dopa)@GM-Cl has high antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Among them, flow cytometry shows that the antibacterial rate of P( l -Dopa)@GM-Cl against E. coli is more than 99%, which is much higher than original membrane (28.4%). P( l -Dopa)@GM-Cl exhibits the enhanced performance in inhibiting biofilm observed by scanning electron microscopy analysis . This work may provide a reference for the construction of anti-biofouling ion exchange membrane.