Improved stable flux and antifouling properties of a PSF gravity-driven membrane by blending with hydrophilic functionalized mesoporous silicon

A new type of hybrid GDM composed of polysulfone (PSF) blended with inorganic mesostructured silicon (SBA-15)-grafted-poly(ethylene glycol)methyl ether methacrylate (PSF/SBA-g-P(PEGMA)) was developed via the non-solvent induced phase separation (NIPS) method. The introduction of hydrophilic SBA-g-P(PEGMA) manipulated the evolution of internal finger-like macrovoids and surface strip-shaped pore structures and promoted membrane surface wettability. The gravity-driven membrane (GDM) filtration of bovine serum albumin (BSA) solution demonstrated that the hybrid membranes exhibited enhanced stable flux and alleviated the normalized flux decline. In particular, when the addition amount of SBA-g-P(PEGMA) was 3 wt%, the stable flux was 5.5 times that of the pristine PSF membrane and the normalized flux decline rate was only 49%. Confocal laser scanning microscopy (CLSM) images confirmed that hydrophilic SBA-g-P(PEGMA) could facilitate the formation of a sparse BSA cake layer. In addition, the BSA filtration experiment at different hydrostatic heights implied that the incorporated SBA-g-P(PEGMA) could relieve the inhibition effect of high hydrostatic pressure on flux stabilization. The GDM filtration tests of natural water for 30 days further indicated that the hybrid membranes provided highly stable flux and high separation performance. This study suggested that the application potential of blending modification with hydrophilic functionalized mesoporous silicon is highlighted in getting through the bottleneck of the GDM system.