Recent development in additives modifications of polyethersulfone membrane for flux enhancement

Polyethersulfone is one of the most important membrane materials and has advantageous chemical and thermal stabilities. With the inherent hydrophobic characteristics of polyethersulfone, this material may be susceptible to fouling during filtration processes. To prevent this fouling, a modification of the membrane is an indispensable step. Various modification techniques had been reported, including the use of additives, chemical treatments, grafting components, and coatings. In this article, the blending/additives modifications of polyethersulfone membranes were performed to increase the membrane flux as well as the hydrophilicity. Three types of additives were introduced, including hydrophilic, amphiphilic, and inorganic materials. The polymeric additives were compatible with good miscibility with the base material, suggesting that these materials may be useful in multiple applications. Several functional groups, such as the sulfonated, pegylated, and carboxylated groups, had excellent miscibility with the polyethersulfone, forming highly hydrophilic membranes with a resistance for protein adsorption. The amphiphilic polymers significantly improved the membrane flux, producing membranes with anti-fouling properties. Several inorganic materials were also used to increase the membrane flux, the hydrophilicity, and the mechanical properties, generating new functional membranes for defined applications. To conclude, the flux enhancement was performed by improvements in the hydrophilicity, roughness, structure, membrane thickness and surface property characteristics of the modified membranes. The blending/additive modifications allowed for improvements in the membrane permeability, the structural features and the surface properties.