Fabrication of Self-Healable Hydrogels through Sol-Gel Transition in Metallo-supramolecular Aqueous Solution by Aeration

A sol–gel transition and the self‐healing of the resultant hydrogels are achieved utilizing a metallo‐supramolecule composed of terpyridine‐terminated low‐molecular‐weight three‐armed poly(ethylene glycol) (trisPEGtpy450) in water at ambient temperature. The gelation of trisPEGtpy450 with cobalt ions occurs by aerobic oxidation (mild conditions), and therefore the solution can be moulded into any shape hydrogel. The solation of the cured hydrogels occurs spontaneously upon the addition of the reductant, and the solution is then re‐gelled by exposure to air due to the consumption of the reductant. Both a sol–gel transition by aeration and self‐healing of the resultant hydrogels without any stimuli are observed when replacing some of the cobalt ions with nickel ions. Self‐healable hydrogels are prepared by a sol–gel transition of a metallo‐supramolecule composed of a terpyridine‐terminated low‐molecular‐weight three‐armed poly(ethylene glycol) (trisPEGtpy450) in water at ambient temperature.