Thin-film nanocomposite membranes for water treatment: Evolution, applications, challenges, and advancement strategies

Thin-film nanocomposite (TFN) membranes have been one of the transformative innovations in membrane technology, addressing some of the critical challenges faced in water treatment, desalination, and gas separation. TFN membranes, by incorporating nanoparticles in the thin polyamide layer of traditional thin-film composite (TFC) membranes, exhibit enhanced permeability, selectivity, fouling resistance, and chemical stability. Improvements in the design of TFN membranes, in terms of their hydrophilic nanomaterials and porous fillers incorporated into the structure, bring about improved water flux and solute rejection, further enabling these membranes to be most effectively efficient in several filtration fields. More importantly, emerging new fabrication techniques allow for the dispersion of nanomaterials in a membrane matrix with great precisions, otherwise suffering from the problems related to nanoparticle aggregation and incompatibility. This review provides an in-depth analysis of the evolution, recent developments, and future perspectives of TFN membrane technology. It presents the ability of TFN membranes to give better performance in the field of reverse osmosis, forward osmosis, and nanofiltration and discusses the challenges in fabrication but also strategizes on ways of optimizing the performance. The review closes with prospects for the application of TFN membranes to address various water-energy challenges globally in a sustainable way.