Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China.
Nanoscale. 2019 Jan 3;11(2):578-586. doi: 10.1039/c8nr07737a.
Conductive rubber nanocomposites have been attracting interest for strain sensing applications owing to their large deformation and high sensitivity. In this paper, the strain sensing behavior of room temperature vulcanized (RTV) hybrid silicone rubber composites containing carbon nanotubes and graphene was systematically investigated. We studied the effects of the nanofiller content and strain amplitude on the strain sensing behavior of the nanocomposites, and found good stability and durability during cyclic loading. The shoulder peaks appeared in the cyclic loading curves owing to the competition between the reconstruction process of the conductive network during deformation and time-dependent features of the polymer material. Furthermore, our test results of different loading histories indicated that a sufficient recovery time could reduce or even eliminate the shoulder peak. Finally, the mechanical structure with a negative Poisson's ratio is designed to regulate the resistance response of the RTV nanocomposites, exhibiting a monotonic and more sensitive resistance response. Our research results explain the main factors contributing to the shoulder peak phenomenon of conductive nanocomposites and provide a regulation strategy for achieving a monotonic and highly sensitive resistance response.
导电橡胶纳米复合材料由于其大变形和高灵敏度而引起了应变传感应用的关注。在本文中，系统研究了含有碳纳米管和石墨烯的室温硫化（RTV）混合硅橡胶复合材料的应变传感行为。我们研究了纳米填料含量和应变幅度对纳米复合材料应变传感行为的影响，并且发现其在循环加载过程中具有良好的稳定性和耐久性。由于在变形过程中导电网络的重构过程和聚合物材料的时变特征之间的竞争，循环加载曲线中出现了肩峰。此外，我们对不同加载历史的测试结果表明，足够的恢复时间可以减少甚至消除肩峰。最后，设计了具有负泊松比的机械结构来调节 RTV 纳米复合材料的电阻响应，表现出单调且更灵敏的电阻响应。我们的研究结果解释了导致导电纳米复合材料肩峰现象的主要因素，并为实现单调且高灵敏度的电阻响应提供了一种调节策略。
