Fabrication of novel thin-film nanocomposite polyamide membrane by the interlayer approach: A review.

Thin-film nanocomposite (TFN) membrane based on polyamide (PA) chemistry was widely applied for water purification and desalination process due to the improved water permeance. It remains a great challenge to significantly enhance rejection because of the non-selective defects caused by the aggregation of nanomaterials in the PA layer. Novel interlayer-based TFN (iTFN) membrane containing nanomaterial interlayer between the porous substrate and PA layer is the promising candidate to improve PA integrity and thus overcome the ubiquitous trade-off between permeability and selectivity. The nanomaterial interlayer not only promotes the subsequent interfacial polymerization (IP) but also provides improved pathways for water transport, which leads to simultaneous improvement in membrane permeability and selectivity. This review systematically categorizes nanomaterial interlayers into three types according to construction methods, namely, direct deposition, in situ growth and functional group-anchored in situ assembly (FAISA). The mechanism of interlayer modulating IP process and PA structure, as well as the effects on water transport, are comprehensively analyzed. Encouraging results reveal that using MOFs interlayer prepared by FAISA is the most promising way to break the trade-off in manufacturing reverse osmosis membranes. Finally, challenges and future efforts are presented for advancing iTFN membranes. [Display omitted] • Recent advances in the porous nanomaterial interlayer enhanced iTFN membranes have been summarized. • Nanomaterial interlayers are categorized into three types according to the construction methods. • The effects of nanomaterial interlayer on interfacial polymerization and separation performance have been explored. • Functional group-anchored in situ assembly MOFs interlayer is a promising candidate to overcome the trade-off between membrane permeability and selectivity. • Challenges and future efforts of promoting nanomaterial interlayer-based iTFN membranes are proposed. [ABSTRACT FROM AUTHOR]