Polymer-based nano-enhanced forward osmosis membranes

Forward osmosis (FO) technology has gained tremendous attention in recent years in desalination and wastewater treatment. Developing a new state-of-the-art FO membranes is vital for advancing the FO technology to achieve commercialization status in the near future. Polymeric membranes such as cellulose triacetate and thin-film composite (TFC) membranes are the only available commercial membranes. Besides being expensive compared to the reverse osmosis membranes, these membranes exhibit lower water flux, high reverse salt flux, prone to irreversible fouling, and have a limited lifetime. The emergence of nanotechnology has enabled researchers to design new membranes with superior performance compared to the commercially available membranes. One promising field is the incorporation of nanomaterials into polymeric membranes to enhance their performance. Researching in this space has resulted in the emergence of a new class of membranes discussed in this chapter. The study covered the synthesis process of flat sheet and hollow fiber membranes modified by incorporation of nanoparticles and discussed stimuli-responsive membranes such as pH-responsive, electric field-responsive, and salt-responsive membranes for water purification. The main challenges associated with the commercialization and future research perspectives are also discussed to identify future research aspects.