López-Barrón Carlos R, Chen Ru, Wagner Norman J
ExxonMobil Chemical Company, Baytown Technology and Engineering Complex, Baytown, Texas 77520, United States.
Center for Neutron Science, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States.
ACS Macro Lett. 2016 Dec 20;5(12):1332-1338. doi: 10.1021/acsmacrolett.6b00790. Epub 2016 Nov 17.
The emerging technologies involving wearable electronics require new materials with high stretchability, resistance to high loads, and high conductivities. We report a facile synthetic strategy based on self-assembly of concentrated solutions of end-functionalized PEO-PPO-PEO triblock copolymer in ethylammonium nitrate into face-centered cubic micellar crystals, followed by micelle corona cross-linking to generate elastomeric ion gels (iono-elastomers). These materials exhibit an unprecedented combination of high stretchability, high ionic conductivity, and mechanoelectrical response. The latter consists of a remarkable and counterintuitive increase in ion conductivity with strain during uniaxial extension, which is reversible upon load release. Based on in situ SAXS measurements of reversible crystal structure transformations during deformation, we postulate that the origin of the conductivity increase is a reversible formation of ion nanochannels due to a novel microstructural rearrangement specific to this material.
涉及可穿戴电子设备的新兴技术需要具有高拉伸性、高负载抗性和高导电性的新材料。我们报道了一种简便的合成策略，该策略基于末端官能化的聚环氧乙烷-聚环氧丙烷-聚环氧乙烷三嵌段共聚物在硝酸乙铵中的浓溶液自组装成面心立方胶束晶体，然后进行胶束冠交联以生成弹性离子凝胶（离子弹性体）。这些材料展现出高拉伸性、高离子导电性和机电响应的前所未有的组合。后者包括在单轴拉伸过程中离子电导率随应变的显著且违反直觉的增加，在负载释放时这种增加是可逆的。基于变形过程中可逆晶体结构转变的原位小角X射线散射测量，我们推测电导率增加的起源是由于这种材料特有的新型微观结构重排导致离子纳米通道的可逆形成。
