Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-10691 Stockholm, Sweden.
J Phys Chem B. 2012 Mar 15;116(10):3198-204. doi: 10.1021/jp209178s. Epub 2012 Mar 2.
Sodium halides, which are abundant in sea salt aerosols, affect the optical properties of aerosols and are active in heterogeneous reactions that cause ozone depletion and acid rain problems. Interfacial properties, including surface tension and halide anion distributions, are crucial issues in the study of the aerosols. We present results from molecular dynamics simulations of water solutions and clusters containing sodium halides with the interatomic interactions described by a conventional force field. The simulations reproduce experimental observations that sodium halides increase the surface tension with respect to pure water and that iodide anions reach the outermost layer of water clusters or solutions. It is found that the van der Waals interactions have an impact on the distribution of the halide anions and that a conventional force field with optimized parameters can model the surface tension of the salt solutions with reasonable accuracy.
氯化钠在海盐气溶胶中含量丰富，它会影响气溶胶的光学性质，并在导致臭氧消耗和酸雨问题的多相反应中具有活性。界面性质，包括表面张力和卤化物阴离子分布，是气溶胶研究中的关键问题。我们通过使用原子间相互作用的传统力场对含有氯化钠的水溶液和团簇的分子动力学模拟，给出了结果。模拟结果再现了实验观察到的现象，即氯化钠会增加相对于纯水的表面张力，并且碘离子到达水团簇或溶液的最外层。研究发现，范德华相互作用会影响卤化物阴离子的分布，并且经过优化参数的传统力场可以合理准确地模拟盐溶液的表面张力。
