writer：Yukun Jian#, Stephan Handschuh-Wang#, Jiawei Zhang*, Wei Lu, Xuechang Zhou* and Tao Chen*
keywords：Biomimetic anti-freezing polymeric hydrogels
source：期刊
specific source：Material Horizons, 2021,8, 351-369
Issue time：2021年

As one of the most outstanding materials, the analysis of structure and function of hydrogels have been extensively carried out to tailor and adapt them to various fields of application. The high water content, which is beneficial for plenty of applications in the biomedical setting, prevents the adaptation of hydrogels for flexible electronics and sensors in real life applications, because hydrogels lose their excellent properties, including conductivity, transparency, flexibility and etc., upon freezing at sub-zero temperatures. Therefore, depressing the liquid-solid phase transition temperature is a powerful means to expand the application scope of hydrogels, and will benefit the chemical engineering and material science communities. This review summarizes the recent research progress of anti-freezing hydrogels. At first, approaches for the generation of anti-freezing (hydro)gels are introduced and their anti-freezing mechanisms and performances are briefly discussed. These approaches are either based on addition of salt, alcohols (cryoprotectants, organohydrogels), ionic liquids (ionogels), modification of the polymer network or a combination of several techniques. Then, a concise overview over applications leveraged by the widened temperature resistance is provided as well as future research areas and developments are envisaged.