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

Adv Sci (Weinh). 2022 Mar;9(7):e2104643. doi: 10.1002/advs.202104643. Epub 2022 Jan 17.

Abstract

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, N2 /CO2 and CH4 /CO2 . It is believed that the new procedure paves the way to a broader range of COF-membranes.

Keywords: COF-membranes; aerogels; covalent organic frameworks; gas mixtures separation; porous materials.