High performance polyester TFC membrane fabricated using vapor-based interfacial polymerization technique for saline water recovery

Abstract

The rapid expansion of industrial processes, such as textile and petrochemical production, generates a large volume of saline wastewater, presenting an opportunity for saline water recovery. While polyamide (PA) thin film composite (TFC) nanofiltration membranes have emerged as a promising technology for saline water recovery, the usage of large amounts of organic solvent and unsustainable amine-based monomers during membrane manufacturing remains a major concern. In this work, we propose a more environmentally friendly method to produce TFC membranes using a hexane-free interfacial polymerization technique. Specifically, the polyester (PE) selective layer of the membranes is created by crosslinking glucose with vaporized trimesoyl chloride (TMC) in a solvent-free environment. By exploring various synthesis parameters, the optimized PE TFC membrane (PE VIP-0.60) can be developed using a glucose concentration of 5 wt% and a sodium hydroxide concentration of 0.05 wt%, with a contact time of 30 min. Our findings revealed that a thinner and looser PE structure contributes to the improvement in membrane performance with respect to pure water permeability (PWP). This optimized membrane exhibited a PWP value 11 times higher than that of the conventional PA TFC membrane (PA VIP-0.60), recording 28.27 L/m².h.bar. Most importantly, the PE VIP-0.60 membrane achieved stable performance during the 8-h filtration of synthetic textile effluent and produced water, achieving >99 % rejection of contaminants, namely Rose Bengal dye and crude oil while recovering >83 % of saline water. In addition, the PE VIP-0.60 membrane showed outstanding chlorine resistance after immersion in sodium hypochlorite solution for 24 h, preserving at least 90 % of the original permeability while exhibiting no significant difference in organic solute rejection.