A rapid self-healing hydrogel based on PVA and sodium alginate with conductive and cold-resistant properties

Self-healing hydrogels as renewable materials have attracted significant attention recently. However, traditional self-healing hydrogels require a long time for self-healing and cannot be used at low temperatures. Besides, their poor biocompatibility limits the application of hydrogels. Herein, we have prepared a hydrogel composed of polyvinyl alcohol (PVA) and modified sodium alginate. Due to the dynamic recombination of borate bonds, these hydrogels show a strong self-healing ability, with the shortest self-healing time up to 15 seconds. Also, glycerin (GI) was added into the hydrogel to increase the cold resistance of the hydrogel. At -25 °C, the hydrogel still displayed good frost resistance and elasticity. NaCl and other inorganic salts were added to endow the hydrogel with good electrical conductivity. The hydrogel also had good skin-like properties and could activate the capacitive screen of an electronic device.