Evaluation of antibacterial and antifouling properties of silver-loaded GO polysulfone nanocomposite membrane against Escherichia coli, Staphylococcus aureus, and BSA protein

Abstract

Herein, the silver-loaded graphene oxide (GO-Ag) was synthesized and used as a nanoadditive to develop the antimicrobial and antifouling polysulfone (PSF) nanocomposite membrane. The antimicrobial property of the prepared membranes was tested against Escherichia coli the representative gram-negative bacteria, and Staphylococcus aureus the gram-positive bacteria. The antifouling characteristic of the membranes was studied by ultrafiltration of bovine serum albumin (BSA) a model protein foulant. The fouling mechanisms were investigated by Hermia's models and the analysis involved fitting the volumetric flux decline experimental data to models. The results revealed that GO sheets were well decorated with spherical Ag of an average ~5 nm diameter. The Ag was dispersed well throughout the outer surface of GO sheets. The antimicrobial results showed that adding GO-Ag nanoadditive into a PSF membrane inhibited the attachment, colonization, and biofilm formation of the microbial species. The fitting of experimental data showed that the all fouling mechanisms were present during the ultrafiltration for PSF membrane using BSA protein but the standard blocking and cake formation mechanisms (R2 ≥ 0.98) dominate the UF processes. The all R2 values (0.70–0.77) of PSF/GO-Ag membrane indicate that the fouling does not occur in the PSF/GO-Ag.