Gao Han, Xu Jianan, Liu Shen, Song Zhongqian, Zhou Min, Liu Shiwei, Li Fei, Li Fenghua, Wang Xiaodan, Wang Zhenxin, Zhang Qixian
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China; University of Science and Technology of China, Hefei 230026, PR China.
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China; University of Chinese Academy of Sciences, Beijing 100039, PR China.
J Colloid Interface Sci. 2021 Sep;597:393-400. doi: 10.1016/j.jcis.2021.04.005. Epub 2021 Apr 8.
Stretchable conductors are susceptible to wear through repeated deformation over time. Stretchable conductors with self-healing properties can increase longevity and reduce safety hazards. However, most current self-healing conductors can only repair either the conductive layer or the insulating layer. Meantime, high mechanical robustness and self-healing efficiency are exclusive especially at ambient conditions. Realizing a stretchable conductor with integral self-healing and ultra-high mechanical strength is challenging, because this requires good interfacial compatibility and adaptability of the conductive and insulating layers. We adapt a biphasic dynamic network strategy to add toughness to self-healing materials. The DOU (dimethylglyoxime-urethane polyurethane) dynamic bonds and hydrogen bonds in the soft phase enable high self-healing efficiency, while the graphene as a hard phase supports the material's superior mechanical properties. We have prepared an overall self-healing stretchable conductor through the soft phase as a self-encapsulating insulating layer. This all-solid (Tg = -49.5 °C) graphene/dimethylglyoxime-urethane polyurethane (Gr/DOU-PU) composites characteristic of both high mechanical strength (6 MPa, ~1000%, ~48 MJ m), self-healing conductivity (90%, 10 min, 25 °C) and conductivity (R□=47.8 Ω □, d = 0.4 mm). The conductor has excellent stability for flexible electronics and for building stress sensors.
随着时间的推移，可拉伸导体容易因反复变形而磨损。具有自修复特性的可拉伸导体可以延长使用寿命并降低安全隐患。然而，目前大多数自修复导体只能修复导电层或绝缘层。与此同时，尤其是在环境条件下，高机械强度和自修复效率是相互排斥的。实现具有整体自修复和超高机械强度的可拉伸导体具有挑战性，因为这需要导电层和绝缘层具有良好的界面兼容性和适应性。我们采用双相动态网络策略来增强自修复材料的韧性。软相中由丁二酮肟-聚氨酯（DOU）形成的动态键和氢键实现了高自修复效率，而作为硬相的石墨烯则支撑了材料优异的机械性能。我们通过将软相作为自封装绝缘层制备了一种整体自修复的可拉伸导体。这种全固态（玻璃化转变温度Tg = -49.5°C）的石墨烯/丁二酮肟-聚氨酯（Gr/DOU-PU）复合材料兼具高机械强度（6 MPa，1000%，48 MJ/m³）、自修复导电性（90%，10分钟，25°C）以及导电性（方阻R□ = 47.8 Ω/sq，厚度d = 0.4 mm）。该导体对于柔性电子产品和构建应力传感器具有出色的稳定性。
