溶解的化离子对液态水中的结合的影响
Jared D Smith1, Richard J Saykally, Phillip L Geissler
1Department of Chemistry, University of California, Berkeley, California 94720, USA.
Journal of the American Chemical Society
|October 26, 2007
概括
将盐添加到水中不会显著改变超越第一个溶解的键网络. 离子电场,而不是结构变化,影响水.
科学领域:
- 物理化学 物理化学
- 化学物理 化学物理
- 材料科学 材料科学 材料科学
背景情况:
- 水溶液中的离子通常被归类为"结构制造者"或"结构破坏者".
- 这种分类部分是基于观察到的水的振动光谱 (拉曼和IR) 的变化.
- 人们普遍认为,盐在结构上大大改变了水的键网络.
研究的目的:
- 为了研究类化盐对液态水的键网络的真正影响.
- 为了确定观察到的光谱变化是由于结构变化或其他因素.
主要方法:
- 在含有化的水中对OH振动光谱的实验测量.
- 先进的计算机模拟模型用于模拟离子-水相互作用和振动光谱.
- 将实验数据与模拟结果进行比较,以验证发现.
主要成果:
- 观察到的OH振动谱的变化主要是由电离子的电场引起的.
- 这些效应局限于直接与离子相邻的水分子 (第一个溶解).
- 在第一个溶解之外的键网络统计数据只受到微弱的影响.
结论:
- 传统的"结构制造者"和"结构破坏者"分类可能过于简单.
- 离子电场,而不是广泛的结构修改,是光谱变化的主要驱动因素.
- 水的键网络比以前认为的更能抵抗离子影响.
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