Ultralarge Free‐Standing Imine‐Based Covalent Organic Framework Membranes Fabricated via Compression

Demand continues for processing methods to shape covalent organic frameworks (COFs) into macroscopic objects that are needed for their practical applications. Herein, a simple compression method to prepare large‐scale, free‐standing homogeneous and porous imine‐based COF‐membranes with dimensions in the centimeter range and excellent mechanical properties is reported. This method entails the compression of imine‐based COF‐aerogels, which undergo a morphological change from an elastic to plastic material. The COF‐membranes fabricated upon compression show good performances for the separation of gas mixtures of industrial interest, N(2)/CO(2) and CH(4)/CO(2). It is believed that the new procedure paves the way to a broader range of COF‐membranes.