Fabrication of ultrafiltration membranes with improved antifouling and antibacterial capability by surface modification of quaternary ammonium

To minimize the organic/biological contamination, polymeric membranes with tertiary amine groups were synthesized and its surface was modified to obtain three types of quaternary ammonium modified ultrafilters. The antifouling and antibacterial properties of all prepared ultrafilters were studied. The performances differences of ultrafiltration membranes with different alkyl chain lengths of quaternary ammonium salts were explored. The results show that the increase of alkyl chain length of quaternary ammonium salts and the introduction of hydroxyl groups can effectively improve the permeability and anti-pollution performance of ultrafiltration membranes. After one cycle of Bovine serum albumin solution filtration test, the flux recovery ratio of the modified membrane is twice as much as that of the initial membrane, while the flux recovery ratio of the initial ultrafiltration membrane is only 36.6%. At the same time, the modified membrane has excellent antibacterial properties and water flux stability, which is conducive to the long-term use of the membrane.