Light- and pH-responsive self-healing hydrogel

A self-healing hydrogel was synthesized via the multi-component reaction of azobenzene-methacrylamide, β-CD and 3-methacrylamido phenylboronic acid. The orthogonal method was applied to analyze the influence of host–guest inclusion complexation, cross-linker and phenylboronic acid monomers content on mechanical properties and healing efficiency of the hydrogel. The results indicated that hydrogel showed autonomic self-healing behavior. The hydrogel demonstrated light-switchable self-healing ability and pH-sensitive swelling ratio. It was found that hydrogel showed high elongation, excellent resilience and low elastic hysteresis. The design of the combined host–guest interactions and boronate esters on the hydrogel showed advantage for improving the mechanical, self-healing and recovery properties simultaneously.