Clermont Université, Laboratoire de Thermodynamique et Interactions Moléculaires, BP 10448, F-63000 Clermont-Ferrand, France.
J Phys Chem B. 2011 Aug 4;115(30):9421-30. doi: 10.1021/jp204056d. Epub 2011 Jul 12.
We report Monte Carlo simulations of the liquid-vapor interface of SO(2), O(2), N(2), and Ar to reproduce the dependence of the surface tension with the temperature. Whereas the coexisting densities, critical temperature, density, and pressure are very well reproduced by the two-phase simulations showing the same accuracy as the calculations performed using the Gibbs ensemble Monte Carlo technique (GEMC), the performance of the prediction of the variation of the surface tension with the temperature depends on the magnitude of the electrostatic and repulsive-dispersive interactions. The surface tension of SO(2) is very well reproduced, whereas the prediction of this property is less satisfactory for O(2) and N(2), for which the average intermolecular electrostatic interactions are several orders smaller than the dispersion interactions. For argon, we observe significant deviations from experiments. The representation of the surface tension of argon in reduced units shows that our calculations are in line with the existing surface tensions of the Lennard-Jones fluid in the literature. This underlines the difficulty of reproducing the temperature dependence of the surface tension of argon with interactions only modeled by the Lennard-Jones pair potential.
我们报告了 SO(2)、O(2)、N(2) 和 Ar 的汽液界面的蒙特卡罗模拟,以再现表面张力随温度的变化。虽然两相模拟很好地再现了共存密度、临界温度、密度和压力,与使用吉布斯系综蒙特卡罗技术 (GEMC) 进行的计算具有相同的准确性,但表面张力随温度的变化的预测性能取决于静电和排斥-分散相互作用的大小。SO(2)的表面张力得到了很好的再现,而 O(2)和 N(2)的预测则不太令人满意,因为它们的平均分子间静电相互作用比色散相互作用小几个数量级。对于氩气,我们观察到与实验的显著偏差。表面张力的还原单位表示,我们的计算与文献中 Lennard-Jones 流体的现有表面张力一致。这强调了仅通过 Lennard-Jones 对势能建模来再现氩气表面张力随温度的变化的困难。