Owing to their high specific surface area, tunable pore sizes, excellent chemical/thermal stability and ability to allow easy modification of the nature of the surface, covalent organic frameworks (COFs) have shown great promise in membrane separation. However, until now, rapid preparation of self-standing COFs membrane has still been a great challenge. In this work, a polyethylene glycol-assisted space-confined strategy for rapid and simple synthesis of imine-linked self-standing COF (TB-DA COF) membranes was developed for the first time. By using this strategy, the molecular organic building unit 1,3,5-tri-(4-aminophenyl)benzene (TB) is confined in a thin layer of polyethylene glycol in conjunction with molecular organic building unit 2,5-dimethoxyterephthalaldehyde (DA). Therefore, the condensation reaction between TB and DA can occur directly without slow diffusion process. In addition, the amorphous-to-crystalline interconversion process can be completed rapidly. Based on this, the imine-based TB-DA COF membrane with high crystallinity can be synthesized within 2 min, which has been the fastest strategy for preparation of COFs membrane to date. The synthesized TB-DA COF₂ membrane showed an excellent rejection (>96%) for dye molecules. This work opens a new fabrication route for COF-based membranes.

由于其高比表面积、可调孔径、优异的化学/热稳定性以及易于改变表面性质的能力，共价有机框架 (COF) 在膜分离中显示出巨大的前景。然而，迄今为止，快速制备自立式COFs膜仍然是一个巨大的挑战。在这项工作中，首次开发了一种聚乙二醇辅助空间限制策略，用于快速简单地合成亚胺连接的自支撑 COF (TB-DA COF) 膜。通过使用这种策略，分子有机结构单元 1,3,5-三-(4-氨基苯基)苯 (TB) 与分子有机结构单元 2,5-二甲氧基对苯二甲醛 (DA ）。所以，TB和DA之间的缩合反应可以直接发生，没有缓慢的扩散过程。此外，可以快速完成非晶到晶体的相互转换过程。基于此，2分钟内即可合成出结晶度高的亚胺基TB-DA COF膜，是迄今为止最快的COFs膜制备策略。合成的 TB-DA COF₂膜对染料分子表现出极好的排斥 (>96%)。这项工作为基于 COF 的膜开辟了一条新的制造途径。