Self-healing and tough hydrogels with conductive properties prepared through an interpenetrating polymer network strategy

Recent years have witnessed great developments in self-healing biopolymeric hydrogel. However, it is difficult to balance the trade-off between self-healing and mechanical properties which limits the applications of these hydrogels. In this article, an interpenetrating polymer network (IPN) hydrogel was fabricated by combining the network of acrylamide-modified chitosan crosslinked with oxidized alginate and the network of polyvinyl alcohol (PVA). This hydrogel showed self-healing ability and improved mechanical properties. The hydrogel could self-heal after incubating for 12 h without external stimulus. In addition, the hydrogels showed better toughness than pure acrylamide-modified chitosan or PVA hydrogel. The IPN hydrogels can recover its original shape after a compression strain of 80%, which exhibited excellent recoverability. Interestingly, the free ions in chitosan and alginate endued the hydrogels with electric conductivity of 0.0046 S cm−1. This self-healing and conductive hydrogels can be used as wires to light LED bulb and be assembled into an electrochromic device. We anticipate that this IPN hydrogel with self-healing, conductive and enhanced mechanical properties can be applied in different engineering fields.