Li Huijun, Zhou Kun
Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
ACS Appl Mater Interfaces. 2023 Sep 20;15(37):44167-44174. doi: 10.1021/acsami.3c06681. Epub 2023 Sep 8.
Hydrogels with high electrical conductivity and mechanical stretchability are promising materials for flexible electronics. However, traditional hydrogels are applied in short-term usage at room temperature or low temperature due to their poor water-retention ability and freezing-tolerance property. Here, a dually cross-linked glycerol-organohydrogel (GL-organohydrogel) based on GL and acrylic acid was synthesized in a GL-water binary solvent. Fe ions working as an electrolyte were added to improve the conductivity of the organohydrogel and form coordination interactions between Fe ions and carboxyl groups of acrylic acid. The strong hydrogen bonding between GL and water molecules firmly lock water in the organohydrogel network, thereby endowing the GL-organohydrogel with the antifreezing property, long-term stability, and moisture lock-in capability. Our organohydrogel could endure extremely low temperature (-80 °C) over 30 days without freezing and retain its water content (almost 100% of its initial state) after being stored at room temperature (25 °C, 54% humidity) for 30 days. It also demonstrated desired stretchable properties, conductivity, three-dimensional (3D) printability, and self-healing ability. A wearable data glove was constructed by using the GL-organohydrogel and digital light processing technology. This work opens a new avenue for developing hydrogels with long-term stability, moisture lock-in capability, and extreme-temperature tolerance for stretchable electronics.
具有高电导率和机械拉伸性的水凝胶是用于柔性电子器件的有前途的材料。然而，传统水凝胶由于其保水能力差和抗冻性能，通常在室温或低温下短期使用。在此，基于甘油（GL）和丙烯酸在GL-水二元溶剂中合成了一种双交联的甘油有机水凝胶（GL-有机水凝胶）。添加作为电解质的铁离子以提高有机水凝胶的电导率，并在铁离子与丙烯酸的羧基之间形成配位相互作用。GL与水分子之间的强氢键将水牢固地锁定在有机水凝胶网络中，从而赋予GL-有机水凝胶抗冻性能、长期稳定性和保湿能力。我们的有机水凝胶可以在极低温度（-80°C）下耐受超过30天而不结冰，并且在室温（25°C，54%湿度）下储存30天后仍保持其含水量（几乎为初始状态的100%）。它还表现出理想的拉伸性能、导电性、三维（3D）可打印性和自愈能力。利用GL-有机水凝胶和数字光处理技术构建了一种可穿戴数据手套。这项工作为开发具有长期稳定性、保湿能力和对可拉伸电子产品的极端温度耐受性的水凝胶开辟了一条新途径。
