Modeling the thermodynamic and physical properties of mixtures of room temperature molten salts (i.e. ionic liquids)

多组分系统的热力学性质（包括相平衡）和物理性质的建模在当今工业上具有重要意义。冶金和化学工业通常使用热化学包来模拟化学反应和相平衡的过程开发。特别是，“室温熔盐”（通常被称为“离子液体”）有许多潜在的应用（如电化学、溶剂和催化剂），与纯液体相比，它们的混合物研究相对较少。多组分盐体系的热力学和相平衡建模包括将相的吉布斯能扩展为温度、压力和组成的函数，并找到一个全局能量最小值。Gibbs能量函数的模型参数是通过优化其值来获得的，以最好地再现文献中发现的实验数据（焓、液相等）。参数形成数据库，模型用于预测多组分系统的相平衡和热力学性质。多组分无机熔盐的密度、粘度和电导率模型都与估算熔体结构的热力学模型相关联，这些模型先前已开发并成功应用于无机电解质，如NaCl-KCl-MgCl2-CaCl2和NaF-AlF3-CaF2-Al2O3-LiF-MgF2。该项目包括建立CX-CY-CZ型共阴离子三元混合物（其中C为大型有机阳离子，X、Y和Z为三种不同的无机阴离子）的相平衡（特别是液相温度）和物理性质（主要是密度和粘度）预测模型和参数数据库，然后是C1X-C2X-C3X型共阴离子三元混合物（其中C1、C2和C3为三种不同的有机阳离子）的模型和参数数据库。而X是无机阴离子)。现有的热力学和物理性质模型将相应地调整/修改，并将根据测量结果进行校准。**********************

Modeling the thermodynamic properties (including phase equilibria) and physical properties of multicomponent systems is of great industrial importance nowadays. The metallurgical and chemical industries commonly use thermochemical packages to simulate chemical reactions and phase equilibria for process development. In particular, "room temperature molten salts" (commonly referred to as "ionic liquids") have many potential applications (such as electrochemistry, and solvents and catalysts), and their mixtures have been studied relatively little in comparison with the pure liquids. The thermodynamic and phase equilibrium modeling of multicomponent salt systems consists in expanding the Gibbs energy of a phase as a function of temperature, pressure and composition, and finding a global energy minimum. Model parameters of the Gibbs energy functions are obtained by optimizing their values in order to best reproduce simultaneously the experimental data found in the literature (enthalpy, liquidus, etc.). Parameters form a database and the models are used to predict phase equilibria and thermodynamic properties in the multicomponent system. Models for the density, viscosity and electrical conductivity of multicomponent inorganic molten salts, all linked to the thermodynamic model that gives an estimation of the structure of the melt, were previously developed and applied successfully to inorganic electrolytes such as NaCl-KCl-MgCl2-CaCl2 and NaF-AlF3-CaF2-Al2O3-LiF-MgF2. The proposed project consists in developing models and databases of parameters for the prediction of phase equilibria (in particular, the liquidus temperature) and physical properties (mainly density and viscosity) of common-cation ternary mixtures of the type CX-CY-CZ (where C is a large organic cation, and X, Y and Z are three different inorganic anions), and then of common-anion ternary mixtures of the type C1X-C2X-C3X (where C1, C2 and C3 are three different organic cations, and X is an inorganic anion). The existing thermodynamic and physical property models will be adapted/modified accordingly, and they will be calibrated on measurements.**********************