Dynamic Interfacial Adhesion through Cucurbit[n]uril Molecular Recognition

Supramolecular building blocks, such as cucurbit[n]uril (CB[n])‐based host–guest complexes, have been extensively studied at the nano‐ and microscale as adhesion promoters. Herein, we exploit a new class of CB[n]‐threaded highly branched polyrotaxanes (HBP‐CB[n]) as aqueous adhesives to macroscopically bond two wet surfaces, including biological tissue, through the formation of CB[8] heteroternary complexes. The dynamic nature of these complexes gives rise to adhesion with remarkable toughness, displaying recovery and reversible adhesion upon mechanical failure at the interface. Incorporation of functional guests, such as azobenzene moieties, allows for stimuli‐activated on‐demand adhesion/de‐adhesion. Macroscopic interfacial adhesion through dynamic host–guest molecular recognition represents an innovative strategy for designing the next generation of functional interfaces, biomedical devices, tissue adhesives, and wound dressings. Dynamic interfacial adhesion of two wet soft materials was accomplished with cucurbit[8]uril‐threaded highly branched polyrotaxanes (HBP‐CB[8]), through CB[8]‐mediated molecular recognition. The dynamic nature of the host–guest complexation imparts interfacial adhesion with astounding toughness, energy dissipation, and reversible bonding upon mechanical failure, as well as on‐demand control over bonding and de‐bonding.