Piedrahita Camilo Rendon, Yue Peijing, Cao Jinwei, Lee Heather, Rajapaksha Chathuranga Prageeth, Feng Chenrun, Jákli Antal, Kyu Thein
Department of Polymer Engineering, University of Akron, Akron, Ohio 44325, United States.
Physics Department, Washington University in St. Louis, St. Louis, Missouri 63130, United States.
ACS Appl Mater Interfaces. 2020 Apr 8;12(14):16978-16986. doi: 10.1021/acsami.0c02328. Epub 2020 Mar 26.
The present article entails the generation of flexoelectricity during cantilever bending of a solid polymer electrolyte membrane (PEM), composed of poly(ethylene glycol) diacrylate (PEGDA) precursor and ionic liquid (hexylmethylimidazolium hexafluorophosphate). The effects of thiosiloxane modification of PEGDA precursor on glass transition, ionic conductivity, and flexoelectric performance have been explored as a function of PEM composition. The glass transition temperature () of the PEM declines with increasing thiosiloxane amount in the PEGDA co-network, while the ionic conductivity improves. The PEM/compliant carbonaceous electrodes assemblies were assembled to determine the flexoelectric coefficients by monitoring electrical voltage/current outputs for various PEM compositions under the intermittent square-wave and dynamic oscillatory sine-wave deformation modes. Of particular interest is that the room temperature flexoelectric coefficient exhibits strong frequency dependence in the vicinity of 0.01-10 Hz, suggesting that ion polarization and ion transport through the ion-dipole complexed networks can still be affected by the mobile side chain branches even in the elastic regime of the covalently bonded PEGDA network. The in-depth understanding of the effect of thiosiloxane side chain on flexoelectricity generation is anticipated to have impact on the development of mechanoelectrical energy conversion devices for energy harvesting applications from natural and dynamical environment.
本文涉及在由聚（乙二醇）二丙烯酸酯（PEGDA）前驱体和离子液体（己基甲基咪唑六氟磷酸盐）组成的固体聚合物电解质膜（PEM）悬臂弯曲过程中产生的挠曲电效应。研究了PEGDA前驱体的硫代硅氧烷改性对玻璃化转变、离子电导率和挠曲电性能的影响，并将其作为PEM组成的函数进行了探讨。随着PEGDA共网络中硫代硅氧烷含量的增加，PEM的玻璃化转变温度（）下降，而离子电导率提高。组装了PEM/柔性含碳电极组件，通过监测在间歇方波和动态振荡正弦波变形模式下各种PEM组成的电压/电流输出，来确定挠曲电系数。特别值得关注的是，室温挠曲电系数在0.01 - 10 Hz附近表现出强烈的频率依赖性，这表明即使在共价键合的PEGDA网络的弹性区域，离子极化和通过离子 - 偶极络合网络的离子传输仍然会受到移动侧链分支的影响。对硫代硅氧烷侧链对挠曲电产生的影响的深入理解，有望对从自然和动态环境中收集能量的机电能量转换装置的开发产生影响。
