Laminated self-standing covalent organic framework membrane with uniformly distributed subnanopores for ionic and molecular sieving.

ABSTRACT: 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.

SUBMITTER: Li Y 

PROVIDER: S-EPMC6992836 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature