ExxonMobil Chemical Company , Baytown , Texas 77522 , United States.
Department of Materials Science and Metallurgy , University of Cambridge , Cambridge CB3 0FS , U.K.
ACS Appl Mater Interfaces. 2018 Sep 26;10(38):32435-32443. doi: 10.1021/acsami.8b10672. Epub 2018 Sep 13.
An ultrastretchable iono-elastomer with resistance sensitive to both elongation strain and temperature has been developed by hierarchical self-assembly of an end functionalized triblock copolymer in a protic ionic liquid (ethylammonium nitrate) followed by cross-linking. Small-angle X-ray scattering experiments in situ with uniaxial elongation reveal a nanoscale microstructural transition of the hierarchically self-assembled cross-linked micelles that is responsible for the material's remarkable mechanical and ionic conductivity responses. The results show that the intermicelle distance extends along the deformation direction while the micelles organize into a long-range ordered face-centered-cubic structure during the uniaxial elongation. Besides good cyclability and resistance to selected physical damage, the iono-elastomer simultaneously achieves an unprecedented combination of high stretchability (340%), highly linear resistance vs elongation strain ( R = 0.998), and large temperature gauge factor (Δ R/ R = 3.24%/°C@30 °C). Human subject testing demonstrates that the iono-elastomer-based wearable thermomechanical sensor is able to effectively and accurately register both body motion and skin temperature simultaneously.
一种超拉伸离子弹性体，通过在质子离子液体（硝酸乙基铵）中原位进行端基功能化的三嵌段共聚物的分级自组装，然后交联，从而具有对伸长应变和温度均敏感的电阻。单轴拉伸的小角 X 射线散射实验原位揭示了分级自组装交联胶束的纳米级微观结构转变，这是材料具有显著的机械和离子电导率响应的原因。结果表明，在单轴拉伸过程中，胶束间距离沿变形方向延伸，而胶束形成长程有序的面心立方结构。除了良好的循环性和对选定物理损伤的抵抗力外，该离子弹性体还同时实现了前所未有的高拉伸性（340%）、高度线性的电阻与伸长应变关系（R=0.998）和大的温度灵敏系数（ΔR/R=3.24%/°C@30°C）的结合。人体试验表明，基于离子弹性体的可穿戴热机械传感器能够有效地、准确地同时记录身体运动和皮肤温度。
