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Updated: Sep 12, 2025

Electrophoretic Crystallization of Ultrathin High-performance Metal-organic Framework Membranes
Published on: August 16, 2018
A covalent organic framework membrane with highly selective and permeable artificial sodium channels via ion
Jing Wang1, Junwei Zhang2, Pengrui Jin3
1Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, School of Environmental Science & Engineering, Huazhong University of Science and Technology (HUST), Wuhan, Hubei, China.
None:
Biological sodium channels efficiently discriminate between same-charge ions with similar hydration shells. However, achieving precise ion selectivity and high throughput in artificial ion channel fabrication remains challenging. Here, we investigate angstrom-scale channels in 15-crown-5 (15C5) functionalized COF membranes for fast, selective ion transport. Due to crown ether recognition of sodium ions, channels in DHTA-Hz-15C5 membranes selectively facilitate Na+ transport, further enhanced by the hydroxyl-enriched COF skeleton. A Na+/K+ selectivity of 58.31 is achieved with 9.33 mmol m-2 h-1 permeance, significantly exceeding current membranes and resembling biological channels. Theoretical simulations indicate one-dimensional COF channels facilitate transport, while crown ether recognition makes the Na+ energy barrier significantly lower than K⁺, enabling ultrahigh selectivity with high Na⁺ permeability. This promotes COFs for efficient single-ion transport and advances crown ether ion selectivity in nano-restricted environments.
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