IF 15.0! Covalent organic framework nanohydrogel

The nano hydrogel of covalent organic frameworks (COFs) will undoubtedly open up new applications for them in water, such as water catalysis and biomedicine. Currently, achieving water dispersion of COF through bottom-up construction strategies or top-down exfoliation techniques is a huge challenge. Here, we successfully designed and synthesized poly (N-isopropylacrylamide) (PNIPAM) post modified COF nanohydrogels (COF NHGs) on COFs scaffolds by in situ atom transfer radical polymerization (ATRP). During the polymer growth process, block shaped COFs are peeled off into nanosheets with a lateral size of approximately 500 nm and a thickness of approximately 6.5 nm. In addition, their size can be precisely controlled by the polymerization degree of PNIPAM. In aqueous solution, the obtained COF-NHG is assembled into a nano hydrogel, which retains the in-plane crystallinity and exhibits a temperature sensitive sol gel phase transition. COF NHGs have excellent solubility in organic solvents, and their inherent physical properties in solution can be characterized by their solution nuclear magnetic resonance and ultraviolet absorption spectra. These results provide a new opportunity to adjust the solution processability of COF and build an intelligent stimulation response platform for COF polymer composite nano hydrogels for equipment applications.