Antibacterial Thin Film Composite Polyamide Membranes Prepared by Sequential Interfacial Polymerization

In this work, thin film composite polyamide (PA) membranes are modified by polyethyleneimine (PEI) and 2,6-diaminopyridine (DAP) through sequential interfacial polymerization to fabricate contact active antibacterial membranes. The modified membranes show improved hydrophilicity and enhancement of zeta potential. Upon tethering with PEI and DAP onto the PA membranes, the membrane flux increases from 35.7 to 46.7 and 50.0 L m(-2)h(-1), respectively. Further the salt rejection rate improves from 96.6% to 98.0% and 98.8%, respectively. The PA-PEI membranes have a better antibacterial performance than PA-DAP, with a bacteria killing ratio for bothEscherichia coli(E. coli) andStaphylococcus aureus(S. aureus) over 96.7%, while a commercial LC LE-4040 membrane presents bacteria killing ratio of 13.3% forE. coliand 8.4% forS. aureus, respectively.