对离子溶液的水合自由能量进行实验编制和计算
Jonathan W Zheng1, William H Green1
1Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
为了改进溶解模型,创建了一个新的水性离子溶解能量 (IonSolv-Aq) 数据集. 这些数据有助于纠正COSMO-RS和SMD等模型中的系统错误,提高对充电溶液的预测.
科学领域:
- 计算化学计算化学
- 物理化学 物理化学
- 化学热力学化学热力学
背景情况:
- 由于实验数据有限,传统的溶解模型难以准确计算离子的溶解能量.
- 现有的数据集,如2012年明尼苏达州溶解数据库,对于对离子溶解进行全面的基准测试是不够的.
- 准确的溶解能量预测对于理解涉及溶液中离子的化学过程至关重要.
研究的目的:
- 介绍IonSolv-Aq,一种新的,基于实验的水性离子溶解能量的数据集.
- 通过使用新数据集,评估隐式解法模型COSMO-RS和SMD的性能.
- 识别和解决当前离子溶液溶解模型中的系统错误.
主要方法:
- 编制了118个离子和155个的无水化能量,以形成IonSolv-Aq数据集.
- 对COSMO-RS和SMD溶解模型与IonSolv-Aq数据集进行比较.
- 对离子溶解能量的模型预测中的系统不确定性和偏移的分析.
主要成果:
- 该IonSolv-Aq数据集的规模是先前对单充电离子的基准数据集的两倍以上.
- 在预测离子溶解能量的过程中,COSMO-RS和SMD表现出系统错误,这些错误可以通过经验参数进行纠正.
- 经过校正后,COSMO-RS在过的测试集上实现了1.7kcal/mol的平均绝对误差 (MAE),SMD显示了类似的性能.
结论:
- 离子溶解-Aq数据集为改善离子溶解模型准确性提供了坚实的基础.
- 在COSMO-RS和SMD中的系统错误可以通过基于实验数据的经验参数化来减轻.
- 开发更大,高质量的实验数据集对于推进溶解建模和准确评估模型性能至关重要.
更多相关视频
11:04Synthesis of Ionic Liquid Based Electrolytes, Assembly of Li-ion Batteries, and Measurements of Performance at High Temperature
Published on: December 20, 2016
08:54Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid
Published on: January 25, 2020
相关概念视频
Aqueous Solutions and Heats of Hydration
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
Electrolytes: van't Hoff Factor
The colligative properties of a solution depend only on the number, not on the identity, of solute species dissolved. The concentration terms in the equations for various colligative properties (freezing point depression, boiling point elevation, osmotic pressure) pertain to all solute species present in the solution. Nonelectrolytes dissolve physically without dissociation or any other accompanying process. Each molecule that dissolves yields one...
Chemical and Solubility Equilibria
Enthalpy of Solution
Energetics of Solution Formation
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Formation of the solution requires the solute–solute and solvent–solvent...
Freezing Point Depression and Boiling Point Elevation
The boiling point of a liquid is the temperature at which its vapor pressure is equal to ambient atmospheric pressure. Since the vapor pressure of a solution is lowered due to the presence of nonvolatile solutes, it stands to reason that the solution’s boiling point will subsequently be increased. Vapor pressure increases with temperature, and so a solution will require a higher temperature than will pure solvent to achieve any given vapor pressure, including one...
