在扩展的疏水界面上的水的定向动力学
Shunhao Xiao1, Florian Figge1, Guillaume Stirnemann2
1Department of Physics and Astronomy, Michigan State University , East Lansing, Michigan 48824, United States.
Journal of the American Chemical Society
|April 6, 2016
概括
在疏水界面上的水分子通过键跳跃迅速重新定位. 这种界面水动态与散装水有很大不同,对表面相互作用有影响.
科学领域:
- 物理化学
- 表面科学
- 光谱学
背景情况:
- 了解水在接口上的行为对于许多化学和生物过程至关重要.
- 疏水界面呈现出独特的环境,影响分子动力学.
研究的目的:
- 研究水分子在疏水界面上的方向动力学.
- 确定在延伸的疏水表面调节水的时间尺度和机制.
主要方法:
- 使用表面特异性振动光谱 (红外可见总频谱).
- 采用了探针异构度测量和同位素稀释以进行详细分析.
- 进行分子动力学模拟以进行比较和机械洞察.
主要成果:
- 由于跳转到结的配置,界面悬挂OH拉伸激发的衰减发生得很快 (1.61 ± 0.10 ps).
- 这种接口跳跃时间比散装水快得多,但比空气/水接口慢得多.
- 悬浮OH的内在种群寿命超过10 ps,表明跳跃占据了观察到的动态.
结论:
- 在疏水界面上的水重定向主要是由快速的键跳跃驱动的.
- 疏水界面稳定OH组,影响它们的动态与空气/水界面相比.
- 模拟支持实验发现,突出介面之间的结构相似性和动态差异.
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