State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.
Laboratory for Biointerfaces, Swiss Federal Laboratories for Materials Science and Technology (Empa), Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.
Sensors (Basel). 2022 Apr 14;22(8):3015. doi: 10.3390/s22083015.
Hydrogels of flexibility, strength, and conductivity have demonstrated broad applications in wearable electronics and soft robotics. However, it is still a challenge to fabricate conductive hydrogels with high strength massively and economically. Herein, a simple strategy is proposed to design a strong ionically conductive hydrogel. This ion-conducting hydrogel was obtained under the synergistic action by salting out the frozen mixture of polyvinyl alcohol (PVA) and graphene oxide (GO) using a high concentration of sodium chloride solution. The developed hydrogel containing only 5 wt% PVA manifests good tensile stress (65 kPa) and elongation (180%). Meanwhile, the PVA matrix doped with a small amount of GO formed uniformly porous ion channels after salting out, endowed the PVA/GO hydrogel with excellent ionic conductivity (up to 3.38 S m). Therefore, the fabricated PVA/GO hydrogel, anticipated for a strain sensor, exhibits good sensitivity (Gauge factor = 2.05 at 100% strain), satisfying working stability (stably cycled for 10 min), and excellent recognition ability. This facile method to prepare conductive hydrogels displays translational potential in flexible electronics for engineering applications.
具有柔韧性、强度和导电性的水凝胶在可穿戴电子产品和软机器人领域显示出广泛的应用。然而，大规模且经济地制备具有高强度的导电水凝胶仍然是一个挑战。本文提出了一种简单的策略来设计一种高强度的离子导电水凝胶。该离子传导水凝胶是通过在高浓度氯化钠溶液的协同作用下，盐析聚氧化乙烯（PVA）和氧化石墨烯（GO）的冷冻混合物而得到的。所开发的水凝胶仅含有 5wt%的 PVA，表现出良好的拉伸应力（65kPa）和伸长率（180%）。同时，少量 GO 掺杂的 PVA 基质在盐析后形成均匀的多孔离子通道，赋予 PVA/GO 水凝胶优异的离子电导率（高达 3.38 S m）。因此，所制备的 PVA/GO 水凝胶作为应变传感器表现出良好的灵敏度（应变 100%时的应变系数为 2.05）、令人满意的工作稳定性（稳定循环 10 分钟）和优异的识别能力。这种制备导电水凝胶的简便方法在用于工程应用的柔性电子产品中具有转化潜力。
