Research Initiation: Development of a Thermodynamic Perturbation Theory for Electrolyte Solutions

本文建立了有限浓度下电解质水溶液的状态方程。该方法基于一种新的热力学摄动理论，其中参考流体被认为是中性和带电球体的混合物。由溶剂极性引起的相互作用被视为扰动。利用有限元法对Ornstein-Zernicke积分方程进行数值求解，得到了新型参考流体的性质。带电对的直接相关函数用HNC方程近似，其他带电对采用PY闭包。通过与计算机仿真的比较，验证了这些相关函数的准确性。在电解质溶液热力学和相平衡的预测描述的发展中，这一基础研究是必需的。这项工作的部分动机是对应用统计力学来描述流体界面的持续兴趣。除了在界面科学的发展中所发挥的作用外，离子溶液的预测性描述对于工业过程的合成和优化，化学复杂水环境的描述以及对某些生物系统的理解都是迫切需要的。

An equation of state of aqueous electrolyte solutions at finite concentrations is developed in this work. The approach is based upon a new thermodynamic perturbation theory in which the reference fluid is taken to be a mixture of neutral and charged spheres. Interactions arising from solvent polarity are treated as the perturbation. The properties of the new reference fluid are obtained from numerical solutions of the Ornstein-Zernicke integral equation using finite element methods. The direct correlation function for charged pairs is approximated by the HNC equation and PY closure used for other pairs. The accuracy of these correlation functions are tested by comparison with computer simulations. This basic research is required in the development of a predictive description of electrolyte solution thermodynamics and phase equilibria. The work is partially motivated by a continuing interest in the application of statistical mechanics to the description of fluid interfaces. Aside from the role played in the development of interfacial science, a predictive description of ionic solutions is urgently needed for the synthesis and optimization of industrial processes, for the description of chemically complex aqueous environments, and for an understanding of some biological systems.