Development of microporous substrates of polyamide thin film composite membranes for pressure-driven and osmotically-driven membrane processes: a review

Abstract

Polyamide thin film composite (TFC) membranes are state-of-the-art membranes with superior permeability and selectivity, and are widely used in various membrane-based processes for desalination, wastewater treatment and other separation applications. Over the past 15 years, there has been growing interest among membrane scientists to study the role of the polymeric substrates and perform in-depth analyses on how changes in the substrate physicochemical properties could affect polyamide layer structure and thus membrane performance. Recent advancements in new polymeric materials development and nanomaterial synthesis have led to opportunities for new generation substrate development. Considering the importance of TFC membranes for industrial separation process, this review will give a state-of-the-art account of the subject matter by emphasizing substrates made by different techniques and various materials. More specifically, the article will review the roles of the developed substrates on the physiochemical properties of polyamide selective layer and further their influences on TFC membrane performance for both pressure-driven (nanofiltration/reverse osmosis) and osmotically-driven (forward osmosis/pressure retarded osmosis) processes, aiming to stimulate progress in the field. A framework for better understanding the substrate development to fulfill the industrial requirements of TFC membrane application will also be presented in this review before ending with future perspectives.