Enhanced performance of inorganic-polyamide nanocomposite membranes prepared by metal-alkoxide-assisted interfacial polymerization

A promising strategy is reported for the synthesis of inorganic-polyamide nanocomposite membranes on an ultrafiltration polysulfone support via metal-alkoxide-assisted interfacial polymerization. Three types of nanocomposite membranes were prepared using three different metal alkoxides. The metal alkoxides used here were titanium tetraisopropoxide, bis(triethoxysilyl)ethane and phenyltriethoxysilane. The as-prepared nanocomposite membranes exhibited performance superior to that of the pure polyamide membrane. Water flux and salt rejection were observed for each of the nanocomposite membranes. Addition of greater amounts of metal alkoxide to the hexane solution increased both pore size and water flux, which were determined by analysis of the membrane permeation data using aqueous solutions of sodium chloride and organic solutes at a pressure of 1.5 MPa and a temperature of 25 °C. The best nanocomposite membrane that was prepared with phenyltriethoxysilane showed water flux that was increased approximately 2-fold compared with the pure polyamide membrane with negligible rejection loss.

Research highlights▶ A promising strategy for the synthesis of inorganic-polymer nanocomposite membranes. ▶ Metal-alkoxide could modify the network structure of the nanocomposite membrane. ▶ Addition of greater amounts of metal-alkoxide increased both pore size and water flux. ▶ Water flux of the nanocomposite membranes was increased significantly at higher PhTES loadings with no rejection loss.