Preparation and Properties of Double Guest-Host and Covalent Crosslinked Anti-Freezing Organic Hydrogel

In this study, a strategy of anti-freezing organic hydrogel system is proposed, which can be used as a medical gel dressing for the prevention and treatment of frostbite in extra cold regions. The supramolecular polymer organic hydrogel is a double network gel dressing. β-Cyclodextrin and azobenzene groups form the first supramolecular network through supramolecular host-guest interaction, and acrylamide copolymerization with crosslinker forms the second layer of covalent network. Compared with acrylamide hydrogels, the stress required to reach the same strain at –25°C is 12 times higher than that at 25°C, while the stress required by organic hydrogels at the same conditions slightly changes, indicating that organic hydrogels also show good flexibility at low temperatures. At the same time, double-network organic hydrogel could recover to 70% of original tensile capacity after self-healing.