| 引用本文格式: Qiao Meng-Dan,Li Fei,Wang Mei-Ling,Zhu Han-Yu,Zhang Yu,Yuan Jun-Sheng. Application of molecular dynamics simulation and Raman spectroscopy to study the hydration phenomena of calcium, magnesium and chloride ions [J]. J. At. Mol. Phys., 2023, 40(1): 011003 (in Chinese) [乔梦丹,李非,王美玲,朱含钰,张宇,袁俊生. 应用分子动力学模拟和拉曼光谱对钙、镁、氯离子 水化现象的研究 [J]. 原子与分子物理学报, 2023, 40(1): 011003] |
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| 应用分子动力学模拟和拉曼光谱对钙、镁、氯离子 水化现象的研究 |
| Application of molecular dynamics simulation and Raman spectroscopy to study the hydration phenomena of calcium, magnesium and chloride ions |
| 摘要点击 536 全文点击 178 投稿时间：2021-08-11 修订日期：2021-09-28 |
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| DOI编号
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| 中文关键词
钙 镁 氯 离子水合作用 分子动力学模拟 拉曼光谱 |
| 英文关键词
Calcium Magnesium Chlorine Ionic hydration Molecular dynamics simulation Raman spectroscopy |
| 基金项目
省市自然科学基金 |
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| 中文摘要
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| 应用分子动力学方法，模拟了298 K下，密度为1.0 g/cm3的水溶液中Ca2+，Mg2+，Cl-的水化现象，得到了相应离子周围水分子的微观分布情况。发现在钙离子周围，水分子以其氧离子去靠近中心离子；而在氯离子周围，水分子则以其中的一个氢原子去靠近中心离子。通过分析三种离子的径向分布函数、配位数曲线、水化数、水化半径，发现Ca2+的水化数和水化半径均大于Mg2+，即Ca2+的水合能力比Mg2+强。与以往研究结果相比，本文计算所得的自扩散系数更接近实验所得结果。为了使模型更好的代表真实水溶液体系，本文还应用分子动力学和拉曼光谱法研究了不同浓度的CaCl2水溶液。分子动力学研究发现随着浓度的升高，CaCl2溶液中Ca2+，Cl-的配位数分别呈降低趋势。同时，随着浓度的升高，Ca2+，Cl-的自扩散系数也呈现降低的趋势。作者推断这是由于浓度的升高，加剧了离子的微观反向运动造成的。拉曼光谱法研究发现随着水溶液中CaCl2浓度的升高，溶液中的氢键网络结构受到了越来越严重的破坏，溶液中Ca2+与Cl-形成的直接接触离子对的数量开始大量增加。
关键词：钙；镁；氯；离子水合作用；分子动力学模拟；拉曼光谱 |
| 英文摘要
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| Using molecular dynamics method, the hydration phenomenon of Ca2+, Mg2+, Cl- in an aqueous solution with a density of 1.0g/cm3 at 298 K was simulated, and the microscopic distribution of water molecules around the corresponding ions was obtained. It was found that around calcium ions, water molecules approached the central ion by oxygen ions; around chloride ions, water molecules approached the central ion by the hydrogen atoms. By analyzing the radial distribution function, coordination number curve, hydration number, and hydration radius, it was found that the hydration number and hydration radius of Ca2+ were greater than those of Mg2+. Therefore, it was speculated that the hydration capacity of Ca2+ was stronger than that of Mg2+. In order to simulate the real aqueous system, the microstructure of CaCl2 aqueous solutions at different concentrations were studied by molecular dynamics and Raman spectroscopy. Molecular dynamics studies found that with the increase of concentration, the coordination number of Ca2+ and Cl- in CaCl2 solution showed a decreasing trend. At the same time, as the concentration increases, the self-diffusion coefficients of Ca2+ and Cl- also showed a decreasing trend. This may be caused by the microscopic reverse motion of the ions. The Raman results showed that with the increase of CaCl2 concentration, the hydrogen bond network structure in the solution was damaged severely. And there appeared more contact ion pairs formed by Ca2+ and Cl-. |
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