Li Yang, Wu Qianxun, Guo Xinghua, Zhang Meicheng, Chen Bin, Wei Guanyi, Li Xing, Li Xiaofeng, Li Shoujian, Ma Lijian
Key Laboratory of Radiation Physics and Technology, Ministry of Education, College of Chemistry, Sichuan University, No. 29 Wangjiang Road, Chengdu, 610064, P. R. China.
Sichuan University-Pittsburgh Institute, Sichuan University, Chengdu, 610207, P. R. China.
Nat Commun. 2020 Jan 30;11(1):599. doi: 10.1038/s41467-019-14056-7.
The preparation of subnanoporous covalent-organic-framework (COF) membranes with high performance for ion/molecule sieving still remains a great challenge. In addition to the difficulties in fabricating large-area COF membranes, the main reason is that the pore size of 2D COFs is much larger than that of most gas molecules and/or ions. It is urgently required to further narrow their pore sizes to meet different separation demands. Herein, we report a simple and scalable way to grow large-area, pliable, free-standing COF membranes via a one-step route at organic-organic interface. The pore sizes of the membranes can be adjusted from >1 nm to sub-nm scale by changing the stacking mode of COF layers from AA to AB stacking. The obtained AB stacking COF membrane composed of highly-ordered nanoflakes is demonstrated to have narrow aperture (∼0.6 nm), uniform pore distribution and shows good potential in organic solvent nanofiltration, water treatment and gas separation.
制备具有高性能离子/分子筛分能力的亚纳米孔共价有机框架（COF）膜仍然是一个巨大的挑战。除了在制备大面积COF膜方面存在困难外，主要原因是二维COF的孔径比大多数气体分子和/或离子的孔径大得多。迫切需要进一步缩小其孔径以满足不同的分离需求。在此，我们报道了一种简单且可扩展的方法，通过在有机-有机界面一步法生长大面积、柔韧、自立的COF膜。通过将COF层的堆叠模式从AA堆叠改变为AB堆叠，膜的孔径可以从>1nm调整到亚纳米尺度。由高度有序的纳米片组成的所得AB堆叠COF膜被证明具有狭窄的孔径（约0.6nm）、均匀的孔分布，并在有机溶剂纳滤、水处理和气体分离方面显示出良好的潜力。
