Thin film nanocomposite forward osmosis membrane embedded with amine-functionalized ordered mesoporous silica

One of the biggest challenges for the preparation of a thin film nanocomposite forward osmosis (TFN-FO) membrane is the lack of adhesion and compatibility between the nanofiller and polyamide matrix. In this study, a novel TFN-FO membrane with high permeability and selectivity was fabricated by interfacial polymerization (IP). Herein, the ordered mesoporous silica (SBA-15) was selected as nanofiller owing to its hydrophilicity and porosity. To improve the compatibility and adhesion between the nanofiller and the polymer matrix, SBA-15 was functionalized with (3-aminopropyl) triethoxysilane (APTES) to introduce active amine groups onto the surface of the nanofiller (SBA-15-NH2), participating in the IP reaction. The effect of the nanofiller on the membrane surface morphology, hydrophilicity, chemical composition, and roughness of the fabricated TFN-FO membranes was systematically investigated using various characterization methods. It was found that the incorporation of SBA-15-NH2 not only improved the surface hydrophilicity but also provided ultrafast nanochannels for water transport. As a result, the novel TFN-FO membrane presented a higher water flux and selectivity compared with the virgin thin film composite (TFC) membrane.