Tetraethylorthosilicate-assisted interfacial polymerization for the fabrication of polyamide thin-film nanocomposite reverse osmosis membranes with enhanced desalination performance

The high-performance polyamide reverse osmosis nanocomposite membrane for desalination was prepared by tetraethylorthosilicate (TEOS)-assisted interfacial polymerization (IP) of 1,3-phenylenediamine in the aqueous phase with 1,3,5-benzenetricarbonyl trichloride in the organic phase on polysulfone ultrafiltration supports. The different contents of TEOS and different IP time were investigated. TEOS is slightly soluble in water and partially hydrolyzed under alkaline conditions. The addition of TEOS during the IP process not only influenced the IP as a co-solvent but also generated inorganic nanoparticles in the polyamide layer in situ as nanofillers to form thin-film nanocomposite membrane. The permeability test showed that the polyamide nanocomposite membrane prepared with 20 wt.% TEOS possesses improved desalination performance. The water flux increased more than twice the pure polyamide composite membrane, and the rejection has been maintained over 95%.