离子加速和减缓水动态的机制
Guillaume Stirnemann1, Erik Wernersson, Pavel Jungwirth
1Department of Chemistry, Ecole Normale Supérieure, UMR ENS-CNRS-UPMC 8640, 24 rue Lhomond, 75005 Paris, France.
Journal of the American Chemical Society
|July 20, 2013
概括
离子影响水的动态局部,而不是远程. 在稀释溶液中,离子效应是添加的,但缩溶液由于重叠的水化和增加粘度而表现出非线性减速.
科学领域:
- 物理化学 物理化学
- 解决方案化学 解决方案化学
- 计算化学计算化学
背景情况:
- 关于水中的离子-溶液相互作用的基本问题仍然存在.
- 离子对水结构和动态的局部和远程影响仍在争论中.
- 了解离子-水相互作用对于各种化学和生物过程至关重要.
研究的目的:
- 研究离子对水的重定向和键动态的影响.
- 区分离子在水溶液中的局部和远程影响.
- 调和关于离子-水动态的相互矛盾的实验发现.
主要方法:
- 水性盐溶液的分子动力学模拟.
- 对离子-水相互作用的分析建模.
- 对水分子重定向和键动态的分析.
主要成果:
- 离子对单个水分子的重定向产生短期影响.
- 离子效应是稀释溶液中的添加物,根据相互作用强度加速或减缓动态.
- 缩溶液表现出水动态的非线性减缓,原因是重叠的水化和增加粘度,这种效应独立于离子类型.
结论:
- 离子对水动态的影响主要是短期的.
- 一个简单的添加模型有效地描述稀释溶液.
- 缩的盐溶液普遍减缓了水的动态,原因是结构变化,而不是离子特异性的合作效应.
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