Mester Zoltan, Panagiotopoulos Athanassios Z
Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, USA.
J Chem Phys. 2015 Jan 28;142(4):044507. doi: 10.1063/1.4906320.
The mean ionic activity coefficients of aqueous NaCl solutions of varying concentrations at 298.15 K and 1 bar have been obtained from molecular dynamics simulations by gradually turning on the interactions of an ion pair inserted into the solution. Several common non-polarizable water and ion models have been used in the simulations. Gibbs-Duhem equation calculations of the thermodynamic activity of water are used to confirm the thermodynamic consistency of the mean ionic activity coefficients. While the majority of model combinations predict the correct trends in mean ionic activity coefficients, they overestimate their values at high salt concentrations. The solubility predictions also suffer from inaccuracies, with all models underpredicting the experimental values, some by large factors. These results point to the need for further ion and water model development.
通过逐渐开启插入溶液中的离子对的相互作用，利用分子动力学模拟获得了298.15 K和1巴下不同浓度的NaCl水溶液的平均离子活度系数。模拟中使用了几种常见的非极化水和离子模型。利用吉布斯-杜亥姆方程计算水的热力学活度，以确认平均离子活度系数的热力学一致性。虽然大多数模型组合预测了平均离子活度系数的正确趋势，但它们在高盐浓度下高估了其值。溶解度预测也存在不准确之处，所有模型都低估了实验值，有些低估幅度很大。这些结果表明需要进一步开发离子和水模型。
