Shinohara Yuya, Matsumoto Ray, Thompson Matthew W, Ryu Chae Woo, Dmowski Wojciech, Iwashita Takuya, Ishikawa Daisuke, Baron Alfred Q R, Cummings Peter T, Egami Takeshi
Materials Science and Technology Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States.
Department of Chemical and Biomolecular Engineering , Vanderbilt University , Nashville , Tennessee 37235 , United States.
J Phys Chem Lett. 2019 Nov 21;10(22):7119-7125. doi: 10.1021/acs.jpclett.9b02891. Epub 2019 Nov 6.
Electrolyte solutions are ubiquitous in materials in daily use and in biological systems. However, the understanding of their molecular and ionic dynamics, particularly those of their correlated motions, are elusive despite extensive experimental, theoretical, and numerical studies. Here we report the real-space observations of the molecular/ionic-correlated dynamics of aqueous salt (NaCl, NaBr, and NaI) solutions using the Van Hove functions obtained by high-resolution inelastic X-ray scattering measurement and molecular dynamics simulation. Our results directly depict the distance-dependent dynamics of aqueous salt solutions on the picosecond time scale and identify the changes in the anion-water correlations. This study demonstrates the capability of the real-space Van Hove function analysis to describe the local correlated dynamics in aqueous salt solutions.
电解质溶液在日常使用的材料和生物系统中无处不在。然而，尽管进行了广泛的实验、理论和数值研究，但对其分子和离子动力学，特别是相关运动的理解仍然难以捉摸。在这里，我们报告了使用通过高分辨率非弹性X射线散射测量和分子动力学模拟获得的范霍夫函数对盐水溶液（NaCl、NaBr和NaI）的分子/离子相关动力学进行的实空间观测。我们的结果直接描绘了皮秒时间尺度上盐水溶液的距离相关动力学，并确定了阴离子-水相关性的变化。这项研究证明了实空间范霍夫函数分析描述盐水溶液中局部相关动力学的能力。
