Probing protein rejection behavior of blended PES-based flat-sheet ultrafiltration membranes: A density functional theory (DFT) study

Membrane fouling is a common problem in membrane technology and causes detrimental effects for the applied membranes such as loss of integrity and productivity. Henceforward, we devoted this work to fabricate membranes that pose favored criteria in the direction of alleviating membrane fouling incidence. Herein, the fabricated membranes were traced via an assortment of both experimental and molecular modeling verifications to understand the mechanism of interaction. To do so, firstly, three different ultrafiltration (UF) membranes had been prepared via facile wet phase inversion method thru dipping a casting solution composed of polyethersulfone-polyvinyl pyrrolidone (PES-PVP) and polyethersulfone-Pluronic P31R1 (PES-P31R1) in a water coagulation bath. Regarding the practical-based data, the pristine PES membrane exhibited the highest rejection of bovine serum albumin (BSA) protein (model foulant) compared with the modified PES-based membranes. The membrane chemical compositions were elucidated with ATR-FTIR Spectroscopy. On the other hand, molecular modeling has been carried out via calculating thermodynamic parameters, level parametric method, and density functional theory (DFT). Thermodynamic parameters analysis indicated that the noticeable difference of BSA rejection may be ascribed to different entropy behavior for the fabricated membranes. In addition, the level parametric method (PM6) and density functional theory DFT: B3LYP with 6-31g (d,p) basis set models clarified the interaction manner of BSA molecules to membrane surfaces.