Polyoxometalate-based anti-freezing hydrogels with high proton conductivity

This is the authors' abstract. We don't add key points for this paper.

With several favorable properties, including flexibility, biocompatibility, and conductivity, conductive hydrogels are one of the most promising flexible sensing materials and are expected to be used in areas such as wearable devices, health monitoring, and electronic skin. However, water in hydrogels freezes at sub-zero temperatures, which greatly affects the performance of hydrogels at low temperatures. Therefore, it remains a challenge to prepare conductive hydrogels that can maintain their performance at low temperatures. In this work, we developed a series of polyoxometalate-based anti-freezing hydrogels with high conductivity by constructing a semi-interpenetrating network using polyacrylamide and sodium alginate, and then introducing H₃PW₁₂O₄₀(HPW) and glycerol into it via a facile soaking strategy. Among the obtained anti-freezing hydrogels, PSWG-50% hydrogel has the proton conductivity of 0.325 <?A3B2 pi129?>S·cm ⁻¹ at room temperature and can maintain high proton conductivity over a wide temperature range from −20 <?A3B2 pi129?>to 65 °C. Based on these advantages, PSWG-50% hydrogel has been used in flexible sensors to monitor human movement, such as limb bending. Whether in mild or cold environments, PSWG-50% hydrogel shows great potential in the field of flexible sensor.