Halide Affinity for the Water-Air Interface in Aqueous Solutions of Mixtures of Sodium Salts
Halide Affinity for the Water-Air Interface in Aqueous Solutions of Mixtures of Sodium Salts
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DOI：
10.1021/jp110208a
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发表时间：
2011-06-16
影响因子：
2.9
通讯作者：
Szleifer, Igal
中科院分区：
文献类型：
--
作者：
Gladich, Ivan;Shepson, Paul B.;Szleifer, Igal
水-气界面在地球大气的许多物理和化学过程中起着关键作用。特别是，重卤离子强烈地参与了通过水-空气界面上的非均相反应确定许多大气成分的普遍性的基本重要过程。在这项工作中，分子动力学模拟被用来研究在氯、溴和碘混合离子的情况下卤化物在水-空气界面的增强。结果表明，增强的模式与阴离子的极化率直接相关。这种效应可以用平板上的电荷分布来解释，这种电荷分布类似于双电层。因此，具有较高极化率的阴离子通过增强它们在界面上的存在来降低系统的势能。
The water-air interface plays a critical role in many physical and chemical processes of the Earth's atmosphere. In particular, heavy halide ions are strongly involved in processes of fundamental importance in determining the prevalence of many atmospheric components through heterogeneous reactions at the water-air interface. In this work, molecular dynamics simulations are used to study the halide enhancements at the water-air interface in the case of mixtures of Cl-, Br-, and I- ions. The results show a pattern of enhancement directly correlated to the anion polarizability. This effect is explained in terms of the charge distribution across the slab resembling an electrical double layer. As a result, the anions with higher polarizability lower the system's potential energy by enhancing their presence at the interface.