Ion Transport in Pendant and Backbone Polymerized Ionic Liquids
Ion Transport in Pendant and Backbone Polymerized Ionic Liquids
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DOI：
10.1021/acs.macromol.8b02682
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发表时间：
2019-09-10
期刊：
影响因子：
5.5
通讯作者：
Runt, James
中科院分区：
文献类型：
--
作者：
Kuray, Preeya;Noda, Takeru;Runt, James
聚合离子液体（PILs）是单离子导体，其中一种离子种类被束缚在聚合物链上，而另一种则可以自由移动。离子种类既可以直接结合到聚合物主链中（主链PILs），也可以作为侧基连接到链上（侧链PILs）。在此，我们研究了基于咪唑的侧链和主链PILs的形态、电导率和流变学。我们发现，当按玻璃化转变温度（T - g）进行换算时，侧链PILs具有更高的离子电导率，但在绝对温度尺度上，主链PILs表现出更高的离子电导率，这可能是由于两个体系的T（g）不同。我们还发现，主链PILs的离子传输在T - g以下与链段动力学相关联，而对于侧链PILs，观察到离子电导率与链段弛豫的解耦现象。这项研究的结果将有助于相关领域更好地理解PIL结构对电导率的作用，从而朝着设计高性能固体聚合物电解质的最终目标努力。
Polymerized ionic liquids (PILs) are single-ion conductors in which one of the ionic species is tethered to the polymer chain while the other is free to be transported. The ionic species can either be directly incorporated into the polymeric backbone (backbone PILs) or placed as pendant groups to the chain (pendant PILs). Here, we examined the morphology, conductivity, and rheology of imidazolium-based pendant and backbone PILs. We found that pendant PILs yielded higher ionic conductivity when scaled to T-g, but backbone PILs exhibited higher ionic conductivity on an absolute temperature scale, likely because of differences in the T(g)s of the two systems. We also found that ion transport for backbone PILs was coupled to the segmental dynamics below T-g, where the decoupling of ionic conductivity from segmental relaxation was observed for pendant PILs. The results of this study will help the community to better understand the role of the PIL structure on conductivity to work toward the ultimate goal of designing high-performance solid polymer electrolytes.