Authors: Xiaochen Zhang, Dong Li, Xuxu Yang, Lei Wang, Guo Li, Tuck-Whye Wong, Tiefeng Li, Wei Yang, Zisheng Luo
Published: 2025-02-27
Source: Full article
Hydrogels consist of cross-linked polymers that are highly swollen with water. Water evaporation or freezing during temperature changes may lead to stiff and brittle hydrogels. We introduce a strategy called “hydro-locking,” which involves immobilizing the water molecules within the polymer network of the hydrogel. This is accomplished by establishing robust connections between water molecules and the polymer by using sulfuric acid. A sacrificial network is introduced to shield the prime polymer network from collapsing. Under the hydro-locking mode, an alginate-polyacrylamide double-network hydrogel remains soft and stretchable within a temperature range that spans from –115° to 143°C. The strategy works with a range of hydrogels and solutions and may enable the preservation and observation of materials or even living organisms at extreme temperatures.