Permeable and antifouling PSf-Cys-CuO ultrafiltration membrane for separation of biological macromolecules proteins

Membrane technology has been extensively applied for protein separation. A membrane with reliable filtration performance and high removal efficiency is required. In this study, an ultrafiltration (UF) membrane was fabricated by dry-wet phase inversion to incorporate copper oxide nanoparticles (CuO NPs) with a different ratio of L-cysteine (Cys) in polysulfone (PSf). The characterization of the membrane involves using scanning electron microscopy (SEM), water contact angle, water content, pore size, and porosity analysis. The membrane performance evaluation includes flux permeation and bovine serum albumin (BSA) removal as a protein foulant. The membrane antifouling feature was examined by dynamic filtration of BSA. It was found that the Cys to CuO NPs ratio of 1.7:1 gives an optimal value on flux permeation and protein removal. The membrane exhibited high removal of BSA with 96.3%, and optimum water flux was achieved at 173.3 L/m2h, respectively. The highest permeability of aqueous BSA permeate at 500 ppm was about 111 L/m2h and 82.5 L/m2h for 1000 ppm. The enhancement of PSf-Cys-CuO membrane performance could be due to its lower contact angle (68.7 degrees), high porosity (68%), and ideal pore size (46 nm) as well as showing good morphological structure. Most significantly, the inclusion of Cys improves antifouling capabilities. The membrane showed a lower chance of fouling based on the evaluation of the relative flux reduction and flux recovery ratio. Hence, the availability of Cys has a better impact on the polymer-based membrane and seems promising for protein separation applications.