Development of braid reinforced hollow fiber membranes as both ultrafiltration and nanofiltration membranes: Effect of pore forming additive on structure and performance

Hollow fiber membranes have higher surface area and are easy to be applied in systems. Because of theirs self-supporting construction, they have limited mechanical durability. By reinforcing these membranes with a braid, the mechanical strength can be improved. In this study, the impact of polyvinyl pyrrolidone (PVP) as a pore-forming additive with different contents on the fabrication of polysulfone braid reinforced hollow fiber membranes was investigated both as a ultrafiltration membrane and as a support for the fabrication of thin film composite (TFC) nanofiltration membranes. Characterization and filtration studies of all membranes were performed to examine membrane performance. It was discovered that the porosity and hydrophilicity of the ultrafiltration membranes were enhanced by enhancing PVP concentration, thus increasing the pure water flux in the membranes. As regards to results of fabricated TFC membranes, salt rejections were increased with increasing PVP ratios. The rejection efficiency of magnesium sulfate and sodium chloride was found to be approximately 80% and 49%, respectively, when a PVP ratio of 8% was used.