Polysulfone/halloysite composite membranes with low fouling properties and enhanced compaction resistance

In the present study, polysulfone (PSF) ultrafiltration membranes incorporated with varying amounts of halloysite nanotubes (Hal) were fabricated via immersion precipitation membrane casting technique. Membrane characterization by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and atomic force microscopy (AFM) revealed that the composite membranes showed notable changes in the morphology, roughness, and distribution of Hal within the membrane matrix. SEM images, pore size, and porosity estimations indicated that the incorporation of low to medium Hal loadings resulted in PSF/Hal membranes with smaller surface pore size, lower porosity, and thicker top skin layer due to the strong interfacial interactions between Hal and PSF matrix. The addition of 5 wt% Hal reduces the composite membrane's contact angle by 14o from the 78.7o of the pristine membrane. The incorporation of 0.2 wt% Hal resulted in a 140% increase in the top surface Young's modulus of the composite membrane, and a notably reduced adhesion of hydrophobic foulants compared to the pristine PSF membrane. During the filtration of bovine serum albumin (BSA) and skimmed milk (SM) solutions, the PSF membranes incorporated with 0.2 and 0.5 wt% Hal showed excellent rejection and flux recovery as well as revealed strong anti-fouling and compaction resistance properties.