This work presents a theoretical study using the electrolyte Cubic-Plus-Association (e-CPA) equation of state combined with quantum chemistry computations, for modeling the density and speed of sound of mixtures containing 2-hydroxyethylammonium-based (2-HEA-based) ionic liquids (ILs) + water/methanol/ethanol over wide ranges of temperatures. The e-CPA ion parameters were estimated by a simultaneous fitting of densities and speed of sounds of pure ILs. Aiming to reduce the number of adjustable parameters, the ion parameters were obtained by COSMO (Conductor-like Screening Model) volume implemented in MOPAC2016 (Molecular Orbital PACkage) based on the geometry optimization of ion structures. The results show that the e-CPA can satisfactorily predict the density and speed of sound of 2-HEA-based ILs + solvents with an absolute average deviation lower than 3%. The addition of two extra binary interaction parameters (solvent-cation and solvent-anion) can further reduce the overall deviation by less than 1%. The sensitivity analysis revealed that only the speed of sound of the 2-HEA-based ILs + solvent mixture is affected by changes in ion radii and dipole moment.

中文翻译：

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使用电解质立方加关联状态方程模拟 2-羟乙基铵基离子液体 + 水、甲醇或乙醇混合物的热物理性质

这项工作提出了一项理论研究，使用电解质立方加缔合 (e-CPA) 状态方程与量子化学计算相结合，对含有 2-羟乙基铵基（2-HEA 基）的混合物的密度和声速进行建模) 离子液体 (IL) + 水/甲醇/乙醇在较宽的温度范围内。e-CPA 离子参数是通过同时拟合纯离子液体的密度和声音速度来估计的。为了减少可调参数的数量，在离子结构几何优化的基础上，通过MOPAC2016（分子轨道PACkage）中实现的COSMO（类导体筛选模型）体积获得离子参数。结果表明，e-CPA 可以令人满意地预测基于 2-HEA 的 ILs + 溶剂的密度和声速，绝对平均偏差低于 3%。添加两个额外的二元相互作用参数（溶剂-阳离子和溶剂-阴离子）可以进一步将总体偏差降低到 1% 以下。灵敏度分析表明，只有基于 2-HEA 的离子液体 + 溶剂混合物的声速受到离子半径和偶极矩变化的影响。