Preparation of hydrogen-bonded supramolecular dual-network hydrogels with tunable mechanical properties

Hydrogel has a wide range of functionalities and great potential for application in various fields. However, the disadvantages such as weak strength and susceptibility to water loss limit its application in complex environments. In this study, glycerol and water were used as binary solvents to construct dual-network hydrogels by mixing polyvinyl alcohol (PVA) and the natural polymer gelatin (GEL) through a simple one-pot method. Glycerol was introduced to form hydrogen bonds with PVA and GEL, on the one hand, resulting in the excellent mechanical properties of the prepared hydrogels; on the other hand, glycerol also endowed the hydrogels with excellent anti-drying and anti-freezing properties, which enabled them to be stably applied in extreme environments. In addition, by adjusting the proportion of glycerol, the mechanical properties of the hydrogel can be adjusted to adapt to the applications in different scenarios. This kind of organic hydrogel with adjustable mechanical properties for anti-drying and anti-freezing has great potential for development in various fields.