(392h) Effects of Polysulfone Support Layer On the Performance of Thin Film Composite (TFC) Membranes

Thin film composite (TFC) membranes are widely used in nanofiltration (NF) or reverse osmosis (RO) for desalination and waste water treatment. In this study, the phase inversion method was used to fabricate polysulfone (PSF) ultrafiltration membrane, and using it as a support layer, the interfacial polymerization (IP) process was applied to create a dense polyamide (PA) thin-film layer for salt rejection. The goal was to assess how the PSF concentration and the addition of polyvinylpyrrolidone (PVP) into the dimethylformamide (DMF) solvent could affect the PSF membrane characteristics and subsequently the performance of the thin film composite (TFC) membrane. The study demonstrated that the water permeability of PSF substrate membrane decreased when the polymer concentration increased. The TFC membrane had a good salt rejection but poor permeability by using the substrate membrane prepared at a higher polymer concentration. In the presence of PVP as an additive to the DMF solvent, PVP at a low concentration increased the water permeability but further increase of PVP concentration to 5% or 10% decreased the permeability. When the substrate membranes with increasing PVP concentration was used in the solvent, the water permeability of the prepared TFC membrane decreased but little change was observed in salt rejection. As a general conclusion, the performance of the TFC membranes depended highly on the casting parameters of the substrate layer.