Hollow mesoporous silica spheres/polyethersulfone composite ultrafiltration membrane with enhanced antifouling property

The growing attention to ultrafiltration (UF) processes from drinking water treatment raises the development of restrain strategy for membrane fouling. In this study, a simple method for fabricating fouling-resistant polyethersulfone (PES) UF membranes is described. The hydrophilic hollow mesoporous silica sphere (HMSS) prepared via surfactant-assembly sol-gel route were blended into PES membranes to enhance the filtration property and fouling resistance. The hydrophilicity of the membrane surface was improved by the integration of HMSS, leading to a reduction in membrane contact angle. When incorporating 1.5% HMSS into the casting solution, the pure water flux reached the maximum (195.7L/m²h) under 0.1MPa while still remained the high rejection to BSA (92.6%). Furthermore, the fouling resistance, especially the irreversible fouling resistance was improved for membrane with 1.5% HMSS compared with the pristine PES membrane using BSA as the model foulant. However, as continue to increase the concentration of HMSS up to 2%, no benefit was brought to the PES membrane owing to particle agglomeration and pore blockage. Furthermore, the UF experiment confirmed that the unique hollow structure of HMSS endowed the UF membrane with improved pure water permeability, comparing with the mesoporous silica spheres (MSS) with solid cores. These characteristics provided the further wide application of composite UF membrane in the drinking water treatment area.