Morphology Control of Polysulfone Membranes in Filtration Processes: a Critical Review

Polysulfone (PSU) membranes have been widely applied in microfiltration and ultrafiltration processes due to their excellent properties, such as chemical inertness across the entire pH range, compressive strength, and thermal stability. Despite these advantages, the application of PSU membranes in filtration processes has often been restricted due to their hydrophobic nature, which results in serious membrane fouling and a reduced permeate flux. Moreover, PSU membranes suffer from several disadvantages, including bulky structure, low binding force between fibers, and poor mechanical properties. The key factor in the development and application of polymeric membranes is the control of its polymeric morphology due to the significant influence of membrane morphology on the membrane performance. Effective techniques of controlling PSU membrane morphology are accessed, and the effects of the morphological control on mechanical properties, chemical stability, membrane performance, and membrane fouling are investigated. Findings from various individual studies were analyzed and discussed in order to provide a critical review of this subject. The results emphasized that the membrane pore size and surface porosity mostly governs PSU membrane morphology, which enhances membrane performance and reduces membrane fouling.