Fig. 2: Structural characterization of 3D SCOF membrane and the schematic for membrane growth mechanism.
From: 3D covalent organic framework membrane with fast and selective ion transport

a FTIR spectra of the monomer A, monomer B and corresponding 3D SCOF membrane. b 13C CP-MAS solid-state NMR spectra of the 3D SCOF membrane. c PXRD patterns of 3D SCOF membrane. The experimentally observed patterns are shown in red, the calculated pattern in black, and their difference in blue. d Schematic for the membrane growth mechanism of single-acid and dual-acid interfacial polymerization process.