Jiang Zhiqi, Shi Xuanyu, Qiao Fenghui, Sun Jingzhi, Hu Qiaoling
MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou310027, China.
Biomacromolecules. 2022 Dec 12;23(12):5239-5252. doi: 10.1021/acs.biomac.2c01058. Epub 2022 Nov 10.
Multistimuli-responsive conductive hydrogels have been appealing candidates for multifunctional ionic skin. However, the fabrication of the multistimuli-responsive conductive hydrogels with satisfactory mechanical property to meet the practical applications is still a great challenge. In this study, a novel poly(-isopropylacrylamide--sodium acrylate)/alginate/hectorite clay Laponite XLS (PNIPAM-SA/ALG/XLS) double cross-linked hydrogel with excellent mechanical property, self-recovery ability, temperature/pH-responsive ability, and strain/temperature-sensitive conductivity was fabricated. The PNSAX hydrogel possessed a moderate tensile strength of 290 kPa at a large elongation rate of 1120% and an excellent compression strength of 2.72 MPa at 90%. The hydrogel also possessed excellent mechanical repeatability and self-recovery ability. Thus, the hydrogel could withstand repetitive deformations for long time periods. Additionally, the hydrogel could change its transparency and volume once at a temperature of 44 °C and change its volume at different pHs. Thus, the visual temperature/pH-responsive ability allowed the hydrogel to qualitatively harvest environmental information. Moreover, the hydrogel possessed an excellent conductivity of 0.43 S/m, and the hydrogel could transform large/subtle deformation and temperature information into electrical signal change. Thus, the ultrafast strain/temperature-sensitive conductivity allowed the hydrogel to quantitatively detect large/small-scale human motions as well as environmental temperature. A cytotoxicity test confirmed the good cytocompatibility. Taken together, the hydrogel was suitable for human motion detecting and environmental information harvesting for long time periods. Therefore, the hydrogel has a great application potential as a multifunctional ionic skin and smart sensor.
多刺激响应性导电水凝胶一直是多功能离子皮肤的理想候选材料。然而，制备具有令人满意的机械性能以满足实际应用的多刺激响应性导电水凝胶仍然是一个巨大的挑战。在本研究中，制备了一种新型的聚（N-异丙基丙烯酰胺-丙烯酸钠）/海藻酸盐/锂皂石粘土Laponite XLS（PNIPAM-SA/ALG/XLS）双交联水凝胶，其具有优异的机械性能、自恢复能力、温度/pH响应能力以及应变/温度敏感导电性。PNSAX水凝胶在1120%的大伸长率下具有290 kPa的适度拉伸强度，在90%应变下具有2.72 MPa的优异压缩强度。该水凝胶还具有优异的机械重复性和自恢复能力。因此，该水凝胶能够长时间承受重复变形。此外，该水凝胶在44℃时会改变其透明度和体积，并在不同pH值下改变其体积。因此，视觉温度/pH响应能力使水凝胶能够定性地获取环境信息。此外，该水凝胶具有0.43 S/m的优异导电性，并且能够将大/微小变形和温度信息转化为电信号变化。因此，超快应变/温度敏感导电性使水凝胶能够定量检测大规模/小规模人体运动以及环境温度。细胞毒性测试证实了良好的细胞相容性。综上所述，该水凝胶适用于长时间的人体运动检测和环境信息采集。因此，该水凝胶作为多功能离子皮肤和智能传感器具有巨大的应用潜力。
