A pH-responsive Self-healing Gel with Crosslinking of Cucurbituril (CB[n]) via Hydrogen Bonding

A novel supramolecular gel has been prepared via hydrogen-bonding interaction between cucurbit[7]uril (CB[7]) and polyacrylamide (PAAm). The amino groups of PAAm are delinked to carbonyls of CB[7] by hydrogen bonding, and the hydrogen-bond interaction was the main driving force for the formation of the supramolecular gel. The sol-gel phase transition, mechanical properties, self-healing property, and the response to pH were examined. We found that CB-PAAm gel has good mechanical properties; besides, pH could control the sol-gel transition and self-assembly of the CB-PAAm gel.