Reversible hydrogel dynamics by physical-chemical crosslink photoswitching using a supramolecular macrocycle template.

Cucurbit[8]uril catalyzes reversible photodimerization of polymer-appended guests, transitioning hydrogel crosslinking from physical to chemical networks. The process of photodimerization is partially reversible, yielding materials with hybrid emergent properties, and which can also be patterned. Accordingly, hydrogels with externally controlled network dynamics are demonstrated.