Monolayer to Bilayer Structural Transition in Confined Pyrrolidinium-Based Ionic Liquids.
Monolayer to Bilayer Structural Transition in Confined Pyrrolidinium-Based Ionic Liquids.
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DOI：
10.1021/jz301965d
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发表时间：
2013-01
期刊：
影响因子：
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通讯作者：
Alexander M. Smith;K. Lovelock;N. Gosvami;P. Licence;Andrew Dolan;T. Welton;S. Perkin
中科院分区：
文献类型：
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作者：
Alexander M. Smith;K. Lovelock;N. Gosvami;P. Licence;Andrew Dolan;T. Welton;S. Perkin
由于离子间力和表面力之间的微妙相互作用，离子液体可以在本体和界面处形成复杂的纳米结构。在这里，我们报告了一系列由限制诱导的二烷基吡咯烷鎓基离子液体的结构。含有具有较短烷基链取代基的阳离子的离子液体在限制到薄膜时形成交替的阳离子-阴离子单层结构，而具有较长烷基链取代基的阳离子导致双层形成。对于这些基于吡咯烷鎓的离子液体，从单层结构到双层结构的交叉发生在n = 8和10的链长之间。 n = 10 的双层结构涉及烷基链的完全交叉；这与之前对咪唑基离子液体的观察结果形成鲜明对比。结果与这些液体作为电解质的应用有关，其中电解质被限制在纳米多孔电极的孔内，例如在超级电容器或电池等设备中。
Ionic liquids can be intricately nanostructured in the bulk and at interfaces resulting from a delicate interplay between interionic and surface forces. Here we report the structuring of a series of dialkylpyrrolidinium-based ionic liquids induced by confinement. The ionic liquids containing cations with shorter alkyl chain substituents form alternating cation-anion monolayer structures on confinement to a thin film, whereas a cation with a longer alkyl chain substituent leads to bilayer formation. The crossover from monolayer to bilayer structure occurs between chain lengths of n = 8 and 10 for these pyrrolidinium-based ionic liquids. The bilayer structure for n = 10 involves full interdigitation of the alkyl chains; this is in contrast with previous observations for imidazolium-based ionic liquids. The results are pertinent to these liquids' application as electrolytes, where the electrolyte is confined inside the pores of a nanoporous electrode, for example, in devices such as supercapacitors or batteries.