Photo-tailored heterocrystalline covalent organic framework membranes for organics separation

• Published in: Nature communications Vol. 13; no. 1; pp. 3826 - 7
• Main Authors: Yuan, Jinqiu, You, Xinda, Khan, Niaz Ali, Li, Runlai, Zhang, Runnan, Shen, Jianliang, Cao, Li, Long, Mengying, Liu, Yanan, Xu, Zijian, Wu, Hong, Jiang, Zhongyi
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 02.07.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 140/131; 140/146; 147/135; 147/143; 639/301/923/1028; 639/638/298/923/1028; 639/925/357/551; Calvin cycle; Chemical industry; Covalence; Crystal structure; Crystallinity; Humanities and Social Sciences; Membranes; multidisciplinary; Science; Science (multidisciplinary); Separation; Solvents
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-31361-w

Organics separation for purifying and recycling environment-detrimental solvents is essential to sustainable chemical industries. Covalent organic framework (COF) membranes hold great promise in affording precise and fast organics separation. Nonetheless, how to well coordinate facile processing—high crystalline structure—high separation performance remains a critical issue and a grand challenge. Herein, we propose a concept of heterocrystalline membrane which comprises high-crystalline regions and low-crystalline regions. The heterocrystalline COF membranes are fabricated by a two-step procedure, i.e., dark reaction for the construction of high-crystalline regions followed by photo reaction for the construction of low-crystalline regions, thus linking the high-crystalline regions tightly and flexibly, blocking the defect in high-crystalline regions. Accordingly, the COF membrane exhibits sharp molecular sieving properties with high organic solvent permeance up to 44-times higher than the state-of-the-art membranes. Covalent organic frameworks (COF) hold great promise in filtration and separation but combining facile processing, high crystallinity and high separation performance remains challenging. Here, the authors demonstrate that heterocrystalline COF membranes in which high-crystalline regions are tightly linked by low-crystalline regions can improve molecular sieving properties at high solvent flux.