Autonomous ultrafast-self-healing hydrogel for application in multiple environments

Self-healing hydrogels have attracted much attention in the fields of biomedicine and wearable electronic devices. However, traditional hydrogels require external stimulation to induce the repair process. Moreover, the relatively weak mechanical properties and long repair time often limit the depth of the hydrogel application. Nevertheless, in this work, we report an ultrafast-self-healing high-strength hydrogel with polyvinyl alcohol (PVA)/diphenylmethane diisocyanate (MDI) as the structural support framework, borax/H3BO3 (BB) solution was used for crosslinking and PVA/glycerin as the dynamic covalent bond. The skeletal structure restricts free PVA segments, and small glycerin molecules form dynamic bonds in a limited area, and thus, a hydrogel with a locally ordered structure is formed. In particular, since numerous hydrogen bonds and dynamic covalent bonds are reversibly formed under the limitation of the skeleton, the hydrogel has a high degree of adaptability and can exhibit self-healing (