Thin film nanocomposite RO membranes: Review on fabrication techniques and impacts of nanofiller characteristics on membrane properties

Abstract

Thin film composite (TFC) reverse osmosis (RO) membrane has been dominating commercial desalination process for several decades since its inception in the 1970s. Despite the ability of generating high quality water at promising water permeability, the commercial TFC RO membrane is still susceptible to fouling and chlorine attack which lead to performance instability as a function of operation time. Over the past decade, the prowess of nanomaterials integration in overcoming the drawbacks of conventional TFC membrane has been proven by many research studies and this has led to the significant progress of thin film nanocomposite (TFN) membrane development. However, it remains a great challenge in integrating the inorganic nanomaterials with the polyamide (PA) selective layer of TFN membrane due to the incompatibility between organic and inorganic materials and the uneven distribution of nanomaterials. In view of this, this article intends to critically review various fabrication techniques that have been developed or modified to incorporate nanofillers within or atop PA layer for the development of TFN membranes. In addition, the essential characteristics of nanofillers in order to achieve good integration with PA layer as well as their impacts in improving membrane performance with respect to water flux, rejection, antifouling, antibacterial and chlorine stability are also reviewed. We hope this review article could provide insights to researchers in fabricating defect-free TFN RO membranes for enhanced water desalination.