In an ionic liquid, high local friction is determined by the proximity to the charge network
In an ionic liquid, high local friction is determined by the proximity to the charge network
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DOI：
10.1063/1.5045675
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发表时间：
2018-10-14
影响因子：
4.4
通讯作者：
Margulis, Claudio J.
中科院分区：
文献类型：
--
作者：
Araque, Juan C.;Margulis, Claudio J.
离子液体（IL）中的结构异质性在很大程度上由纳米级非极性口袋限定，所述非极性口袋充当交替的正电荷和负电荷的串之间的间隔物。与此相反，我们小组和其他人最近的工作似乎表明，动态的，充满活力的，和机械的不均匀性是由液体的带电部分。在这篇文章中，我们研究了甲烷，一个小的非极性溶质，在家庭的离子液体1-烷基-3-甲基咪唑双（三氟甲基磺酰基）酰亚胺（Im（1，n）（+）/NTf 2-），n = 2，4，8在温度下，使每种液体的粘度相似，约8 cP。我们这样做是为了平衡溶剂对溶质动力学的影响。在所有情况下，我们发现，溶质接近电荷增强区相一致的conventionally笼制度（高局部摩擦），而相反的是真实的电荷耗尽区。在某种程度上，这些离子液体表现得像液体中的液体，其中电荷网络是高摩擦组件。出版社：AIP Publishing
Structural heterogeneity in Ionic Liquids (ILs) is to a large extent defined by nanoscale apolar pockets that act as spacers between strings of positive and negative charges that alternate. In contrast to this, recent work from our group and that of others appear to indicate that dynamic, energetic, and mechanical heterogeneities are governed by the charged part of the liquid. In this article, we study the dynamics of methane, a small apolar solute, in the family of ILs 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide (Im(1,n)(+)/NTf2-), with n = 2, 4, 8 at temperatures that make the viscosity for each liquid similar and around 8 cP. We do this in an attempt to equalize the effect of the solvent on the dynamics of the solute. In all cases, we find that solute proximity to charge-enhanced regions coincides with translationally caged regimes (high local friction) whereas the opposite is true in charge-depleted regions. In a way, these ILs behave like a liquid within a liquid where the charge network is the high friction component. Published by AIP Publishing.