Engineering design of a biofilm formed on a pH-sensitive ZnO/PSf nanocomposite membrane with antibacterial properties

Abstract

In this research, zinc oxide (ZnO) nanoparticles were used on a matrix of a polysulfone ultrafiltration membrane to make a nanocomposite membrane with a positive surface charge for filtration of biological macromolecules. The engineering of the biofilm structure developed onto the membrane surface leads to increased membrane flux, elevated rejection of protein, and reinforced antifouling properties of the membrane. AFM results indicated that the formed biofilm has increased roughness at higher pH levels. Further, FTIR analysis proved that the extent of biological macromolecules deposited on the membrane surface is greater at higher pHs. Through engineering the conditions of nanocomposite fabrication and adjustment of pH of the protein solution, the best antifouling performance was related to the nanocomposite containing 0.5 wt% of nanoparticles at pH of 8.9. Antibacterial tests proved the antibacterial properties of the nanocomposites containing ZnO nanoparticles.