Solvothermal synthesis of microporous, crystalline covalent organic framework nanofibers and their colorimetric nanohybrid structures.

This paper reports a facile solvothermal approach for the design and synthesis of novel crystalline COF nanofibers with amazing properties. An interesting morphological transformation from microsphere to nanofibers was observed, which could be supported by the unique dissolution-recrystallization mechanism due to the reversible nature of dynamic imine bonding. Interestingly, it was also found that the COF nanofibers could epitaxial grow on the aramid microfiber surface. This functional nanocomposite showed an interesting colorimetric humidity-responsive behavior. Our study provides a general methodology for the fabrication of COFs with designated micronanostructures and has more implications on their applications in catalyst and sensors.