Developing high-performance thin-film composite forward osmosis membranes by various tertiary amine catalysts for desalination

A desirable membrane with high separation performance, excellent antifouling properties, and chemical stability is important to the advance of forward osmosis (FO) technology in the wastewater treatment and desalination processes. In this work, three different tertiary amines, i.e., tri-ethylamine (TEA), tris(2-aminoethyl) amine (TAEA), and hexamethylenetetramine (HMTA), are employed as catalysts to accelerate the interfacial polymerization (IP) reaction for constructing the PA layer with optimized properties and performance of the resulting membranes. For the first time, the effect of different tertiary amines on the microstructure, morphology, and surface properties of formed PA layers, as well as the separation performance, fouling, and chemical resistance of the resulting TFC membranes, are studied systematically with various characterization techniques. As compared with the control membrane, modified membranes exhibit obviously improved separation performance and greater potential in the desalination process. Furthermore, modified membranes also exhibit improved fouling resistance and chemical stability. Therefore, the tertiary amine modification of TFC membranes may shed a new light for their future applications in harsh conditions. Graphical abstract