Thermophysical Properties of Imidazolium-Based Binary Ionic Liquid Mixtures Using Molecular Dynamics Simulations
Thermophysical Properties of Imidazolium-Based Binary Ionic Liquid Mixtures Using Molecular Dynamics Simulations
复制标题
使用分子动力学模拟的咪唑基二元离子液体混合物的热物理性质
DOI：
10.1021/acs.jced.7b01028
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发表时间：
2018
影响因子：
--
通讯作者：
Shah, Jindal K.
中科院分区：
文献类型：
--
作者：
Kapoor, Utkarsh;Shah, Jindal K.
直到最近，通过改变阳离子、阴离子或两者的化学性质来设计特定于任务的离子液体。另一种获得相当大动力的方法是考虑离子液体，其来源于混合两种不同的离子液体并改变这种共混物的摩尔组成，以对所需的物理化学和生物学性质进行精确控制。由于混合产生的离子液体的数量预计接近十亿，因此非常希望优先预测离子液体混合物是否可以被认为是其纯类似物的理想溶液。为此，我们采用分子动力学模拟预测的密度，摩尔体积，过量摩尔体积，自扩散系数，和离子电导率为11个离子液体混合物系统作为跨越整个范围的组成离子液体的摩尔分数的函数。这里研究的离子液体混合物是1-正丁基-3-甲基咪唑鎓 [C4 mim]+氯化物Cl-与[C4 mim]+乙酸盐[CH 3COO]−/[OAC]−、[C4 mim]+三氟乙酸盐[CF 3COO]−/[TFA]−和[C4 mim]+三氟甲磺酸盐[CF 3SO 3]−/[TFS]−配对，以及[C4 mim][OAC]与[C4 mim][TFA]和[C4 mim][TFS]组合。通过与1-乙基-3-甲基咪唑[C2mim]+、1-正己基-3-甲基咪唑[C6 mim]+和1-正辛基-3-甲基咪唑[C8 mim]+阳离子的偶联，研究了烷基链长变化对含Cl--甲基硫酸根[MeSO 4]−和Cl--双（三氟甲磺酰基）酰亚胺[NTf 2]−阴离子的离子液体混合物热物理性质的影响。从线性混合规则的属性趋势的偏差进行了讨论的纯离子液体类似物的性质的差异。
Until very recently, task-specific ionic liquids have been designed by altering the chemistry of either the cation, anion, or both. An alternative approach, that is gaining considerable momentum, is to consider ionic liquids that are derived from mixing two different ionic liquids and varying the molar composition of such blends to exert precise control over the desired physicochemical and biological properties. As the number of ionic liquids that result from mixing is projected to be close to a billion, it is highly desirable to predicta prioriwhether ionic liquid mixtures can be considered as ideal solutions of their pure analogues. Toward this end, we employ molecular dynamics simulations to predict the density, molar volumes, excess molar volumes, self-diffusion coefficients, and ionic conductivities for 11 ionic liquid mixture systems as a function of mole fractions spanning the entire range of compositions of the constituent ionic liquids. The ionic liquid mixtures investigated here are 1-n-butyl-3-methylimidazolium [C4mim]+chloride Cl–paired with [C4mim]+acetate [CH3COO]−/[OAC]−, [C4mim]+trifluoroacetate [CF3COO]−/[TFA]−and [C4mim]+trifluoromethanesulfonate [CF3SO3]−/[TFS]−, and [C4mim][OAC] combined with [C4mim][TFA] and [C4mim][TFS]. The effect of change in the alkyl chain length on the thermophysical properties of ionic liquid mixtures containing anions as Cl––methylsulfate [MeSO4]−, and Cl––bis(trifluoromethanesulfonyl)imide [NTf2]−is evaluated by coupling with 1-ethyl-3-methylimidazolium [C2mim]+, 1-n-hexyl-3-methylimidazolium [C6mim]+, and 1-n-octyl-3-methylimidazolium [C8mim]+cations. The deviation of the property trend from the linear mixing rule is discussed in terms of the difference in the properties of pure ionic liquid analogues.