Fig. 5: Interfacial polymerization for COF membrane preparation.

a, b Schematic view of the polymerization and crystallization process of node and linker, and the prepared highly strong, tough, and elastic single-crystal 2D COF membranes. Polyacrylic acid as a template and diethylenetriamine as a sacrificial go-between to direct the growth and crystallization of COF membranes. Reproduced with permission from ref. ¹¹⁷ (copyright Springer Nature, 2024). c Synthesis scheme and macroscopic appearance of the TFC-COF membrane, as well as the experimental procedures adopted to assess its mechanical robustness via rubber roller rolling and sandpaper scrubbing. The corresponding SEM images of the membrane before and after abrasion are also provided¹²¹ (copyright Elsevier, 2022). d Schematic of the TFC-COF membrane fabrication process, digital photos of the resulting ~1 m² membrane and different folding shapes, and a corresponding SEM image of the membrane. Reproduced with permission from ref. ¹²² (copyright Springer Nature, 2025).