Light- and pH-responsive self-healing hydrogel

A self-healing hydrogel was synthesized via the multi-component reaction of azobenzene-methacrylamide, -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.