Transient Healability of Metallosupramolecular Polymer Networks Mediated by Kinetic Control of Competing Chemical Reactions

The research on intrinsic self-healing chemistry based on the kinetic lability of chemical bonds/physical interactions is particularly interesting in renewable/sustainable polymer science due to its importance in allowing for multiple local healing events to occur. One common problem with the kinetic lability is the negative effect on the stability of polymer materials. Herein, we present a hierarchical strategy for temporal control of the intrinsic healability of kinetically inert and highly stable metallosupramolecular polymer networks. Enzyme-regulated competing reactions are used for temporal programming of an oxidation state change of metal ions in the cobalt cross-linked polymer hydrogels, which, in turn, tunes the metal–ligand interactions for efficient defect healing and hydrogel property recovery. The hydrogels exhibit high stability under harsh conditions and excellent healability with ∼100% recovery by the intake of proper chemical nutrients. Our approach advances the intrinsic healing of kinetically stable metallosupramolecular polymer hydrogels without compromising their composition and homogeneity.