Preparation and characterization of SLS-CNT/PES ultrafiltration membrane with antifouling and antibacterial properties

Abstract

Carbon nanotubes (CNTs) were functionalized by a simple non-covalent modification with sodium lignosulfonate (SLS), and the hybrid polyethersulfone (PES) ultrafiltration membranes were prepared by phase inversion method with different ratios of functionalized carbon nanotubes (f-CNTs). SEM analysis indicated that obvious finger-like pores appeared in f-CNT/PES hybrid membranes. The f-CNTs were uniformly dispersed on the membrane surface, causing super hydrophilicity and high water flux of the f-CNT/PES hybrid membranes. Filtration and protein adsorption tests indicated that the antifouling performances were dramatically increased, the amount of protein pollutants adsorbed by the hybrid membranes was significantly lower than the nascent membranes, and most of the water flux can be recovered after three cycles of the BSA solution fouling process. The antibacterial tests confirmed that no prepared membranes showed excellent antibacterial properties to Escherichia coli (E. coli). However, the hybrid membrane showed good antibacterial properties treated with a low-voltage electric field (direct current (DC), about 1.5Vcm−1), and the antibacterial rate (AR) closed to 100% after testing for 3h.