Nano-confined controllable crystallization in supramolecular polymeric membranes for ultra-selective desalination

Journal article

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.

Authors: Lu, G; A, H; Zhao, Y; Zhao, Y; Xu, H

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Nature Research
• Journal: Nature Communications
• Volume: 16
• Issue: 1
• Article number: 2284
• Publication date: 2025-03-07
• Acceptance date: 2025-02-19
• DOI: 10.1038/s41467-025-57353-0
• EISSN: 2041-1723
• ISSN: 2041-1723
• Language: English