Host–guest interaction-mediated fabrication of a hybrid microsphere-structured supramolecular hydrogel showing high mechanical strength†
The introduction of structured microsphere composites into hydrogels is found to improve their mechanical strength capability. Herein, chitosan microspheres were functionalized with poly(acrylamide-co-1-benzyl-3-vinylimidazolium bromide) (CS–P(AM–G)), which was synthesized through an in situ copolymerization of acrylamide and a guest functional monomer. Supramolecular hydrogels were fabricated by dynamic host–guest interactions between guest units and the host molecule cucurbituril (CB). Investigations on the mechanical properties of the hydrogels show that the tensile stress and the compress stress of the hydrogels are five times higher than those of CB hydrogels without CS, and the healing efficiency of the hydrogels at room temperature is 88% after 24 h. The results show that CS microspheres serve as both polyfunctional initiating and cross-linking centers, whereas the dynamic host–guest interactions endow the hydrogels with a higher self-healing property. The process provides a novel method for the production of tough and self-healing supramolecular hydrogels with various potential applications.