Chitin/Ca solvent-based conductive and stretchable organohydrogel with anti-freezing and anti-drying.

Conductive hydrogel flexible sensors have attracted considerable research interest because of their good conductivity, flexibility, and biocompatibility. However, conventional hydrogels suffer from dehydration under ambient environments and freezing at low temperatures. Herein, we prepared a chitin/polyacrylamide organohydrogel with highly stretchable, anti-freezing, and anti-drying properties. This organohydrogel was creatively prepared by one-step radical polymerization in the chitin and calcium chloride/methanol (Ca solvent) aqueous solution. Benefiting from the chitin/Ca solvent system, the organohydrogel shows relatively high stretchability (improve ~5 times), excellent anti-freezing (up to -80 °C) upon long-term storage, and anti-drying (67 days under normal environment) performance. What's more, the reversible noncovalent bonds in the organohydrogel endow it with repeatable multi-purpose adhesion and rapid self-healing, while the abundant free ions grant it good conductivity to be a flexible sensor. Therefore, it is promising that this chitin-based conductive organohydrogel with multifunctionality would provide wide application scopes of flexible electronic devices.