Nano-confined controllable crystallization in supramolecular polymeric membranes for ultra-selective desalination
Year: 2025
Type: article
Abstract: Innovations in self-assembly and aggregate engineering have led to membranes that better balance water permeability with salt rejection, overcoming traditional trade-offs. Here we demonstrate a strategy that uses multivalent H-bond interactions at the nano-confined space to manipulate controllable and organized crystallization. Specifically, we design amphiphilic oligomers featuring hydrophobic segments with strongly polar end-capped motifs. When spreading on air/water interfaces, the hydrophobic parts repel water, yielding an ordered alignment of supramolecular oligomers under nano-confinement, while the strongly polar sections engage in strong hydrogen bonding and reconfigure to strongly interact with water molecules, enabling the controlled assembly and orientation of nano-confined crystalline domains. This arrangement provides dual benefits: refining the distribution of pore sizes for ultra-selectivity and boosting the free volume for water permeation. Compared to counterpart oligomers with weakly polar motifs, the optimized membrane with a 6-nm thickness demonstrates the water permeability of 14.8 L m−2 h−1 bar−1 and extraordinary water/NaCl selectivity of more than 54 bar−1 under pressure-driven condition. This study sheds light on how nano-confined self-assembly and aggregate engineering affect the architectures, functionality, and performance of polymer membranes, emphasizing the promise of controllable crystallization in ultrathin membranes for optimal desalination. Membranes with a balance between water permeability and salt rejection are desirable, and can be developed through self-assembly and aggregation. Here, the authors report a hydrogen-bonding strategy in a nanoconfined space to give controlled crystallisation, for membranes for reverse osmosis.
Source: Nature Communications
Institutions: City University of Hong Kong, Wuhan University, State Key Laboratory of Water Resources and Hydropower Engineering Science, Hong Kong Polytechnic University, KU Leuven, Tsinghua University, Jinan University, RMIT University, Harbin Engineering University, Shenzhen University, University of Oxford, Hong Kong University of Science and Technology, University of Hong Kong
Language: English
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $6,990
Funders: City University of Hong Kong, University of Oxford, RMIT University, National Natural Science Foundation of China, Chinese Academy of Sciences, Innovation and Technology Commission, Harbin Engineering University, University of Hong Kong, Jinan University, KU Leuven, Tsinghua University, Hong Kong Polytechnic University, Hong Kong University of Science and Technology, Wuhan University, Shenzhen University, State Key Laboratory of Water Resources and Hydropower Engineering Science
OpenAlex ID: W4408233120