Self-healing and conductivity of chitosan-based hydrogels formed by the migration of ferric ions

The currently reported self-healing hydrogels have problems of low mechanical strength, single performance, and poor self-healing efficiency, which greatly limit their applications. Here, through adding N-carboxyethyl chitosan to acrylic-Fe3+ system, the self-healing physically crosslinked hydrogels were prepared via in situ free radical polymerization, which have excellent self-healing ability and mechanical properties. The maximum tensile strength and elongation at break of the hydrogels can reach up to 280 KPa and 1900%, respectively. Owing to the reversibility of coordination, self-healing efficiency of the hydrogels can reach 98% in 2.5 h. Moreover, the hydrogels also have good conductivity due to the migration of Fe3+. This strategy can broaden the applications of chitosan-based self-healing hydrogels. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47885.