Role of Organic Acids in Flux Enhancement of Polyamide Nanofiltration Membranes

Abstract

A novel TFC nanofiltration membrane containing hydrophilic organic additives was fabricated via interfacial polymerization method. To this end, three organic acids (lactic, maleic and citric acid) were applied as aqueous phase additives and their role in membrane structure and nanofiltration membrane flux enhancement was investigated. The FT-IR analysis confirmed the presence of organic acids in PA layer. The SEM and AFM analysis also were o applied to investigate membrane morphology. The more carboxylic functional group present in the additive resulted in the higher hydrophilicity and porosity and the more flux enhancement as the membrane containing 0.75w/w% citric acid show more than 50% increment rather than neat PA membrane, while the salt rejection was not sacrificed considerably.