Polyamide reverse osmosis membranes containing 1D nanochannels for enhanced water purification

• Published in: Journal of membrane science 2021-01, Vol.618, p.118681, Article 118681
• Main Authors: Li, Wen-xuan, Yang, Zhe, Liu, Wei-liang, Huang, Zhi-hao, Zhang, Hao, Li, Meng-ping, Ma, Xiao-hua, Tang, Chuyang Y., Xu, Zhen-liang
• Format: Article
• Language: English
• Subjects: Copper hydroxide nanorods (CuNRs); Reverse osmosis; Thin-film composite membrane
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2020.118681

Thin-film composite (TFC) reverse osmosis (RO) membrane is the gold-standard for desalination and water reuse. Recent literature highlights the importance of polyamide (PA) rejection layer containing nanovoids to manipulate the water permeability and salt rejection. In this study, a facile template-assisted approach was applied to generate one-dimensional (1D) nanochannels in the polyamide rejection layer of RO membranes by preloading copper nanorods inside the PA layer followed by acid etching. In addition, a TFC RO membrane containing 0D nanovoids was also fabricated to compare the dimensional effect of nanochannels on membrane morphologies and performances. Specifically, the TFC-0D membrane only exhibited 61% higher water permeability compared to that of the control TFC, while the TFC-1D membrane showed 126% higher water flux with similar NaCl rejection, probably due to the dimensional improvement of the nanochannels inside the rejection layer. This templates-assisted approach paves a feasible way for fabricating high-performance next-generation RO membranes. [Display omitted] •A facile template-assisted approach to generate one-dimensional nanochannels in polyamide layer.•Nanochannels-contained showed 126% higher water flux with similar NaCl rejection compared to the control.•The dimensional improvement from nanovoids to the nanochannels brought great effectiveness in water flux.•Cross-sectional and back surface images of the polyamide layer proved the existence of nanochannels.