Effect of Addition of Iron Salt in Amine Solution on Performance of Polyethylene Imine-lsophthaloyl Chloride (PEI-IPC) based Polyamide-Polysulfone Composite Reverse Osmosis (RO) Membranes

摘要

In this study, we report the effect of addition of iron salts with amine reactants on the performances of thin-film composite (TFC) polyamide reverse osmosis membranes prepared by in-situ interfacial polymerization between polyethylene imine (PEl) and 1, 3-benzene dicarbonyl chloride or isophthaloyl chloride (IPC). Iron salts are added with the aqueous solution of the polyethylenimine (PEl) (contains primary, secondary and tertiary amine groups in a 1:2:1 ratio) prior to the reaction with hexane solution of isophthaloyl chloride (IPC) to block some of the amine groups. TFC membranes prepared with and without iron salts are characterized in terms of separation characteristics for sodium chloride and magnesium sulfate solutes, water contact angle and atomic force microscopy studies. Membranes prepared using PEl solution containing iron salts are generally more hydrophilic with rougher surface and show better separation performances than the membranes prepared without iron salt and the same trend is observed with PEl of different molecular weights. The reaction time needed to complete polyamide thin film formation is less for iron salt containing PEl than the blank PEl solution under identical preparation condition.