通过二维红外光谱学研究AOT层内部的动力学
S K Karthick Kumar1, A Tamimi, Michael D Fayer
1Department of Chemistry, Stanford University , Stanford, California 94305, United States.
Journal of the American Chemical Society
|March 8, 2013
概括
使用超快速光谱学研究气溶-OT (AOT) 水混合物,与液态环境相比,在有序相中揭示了不同的分子动力学. 这些动态受到水分水平的影响,影响探头分子.
科学领域:
- 物理化学 物理化学
- 材料科学 材料科学 材料科学
- 频谱学是一种光谱学.
背景情况:
- 气溶OT (AOT) 与水形成复杂的中相,对各种应用至关重要.
- 了解这些有组织结构中的分子动力学是控制它们属性的关键.
研究的目的:
- 为了研究AOT/水混合物的有机区域内的超快速动态.
- 为了比较状和双连续立方 (BC) 阶段与非离子模拟器 (EHS) 的动态.
- 为了确定水合对分子运动的影响.
主要方法:
- 超快的二维红外 (2D IR) 振动回声光谱.
- 红外 (IR) 探头实验使用六碳 (W(CO) 6作为振动探头.
- 通过频率-频率相关函数 (FFCFs) 分析光谱扩散.
主要成果:
- 在AOT叶片和BC阶段的FFCF显示了 biexponential衰变 (快速~12.5 ps,缓慢~150 ps).
- 在有序的AOT阶段的动力学显著低于液体EHS模拟 (快速~5 ps,慢~80 ps).
- 在AOT叶片阶段增加的水分会导致W(CO) 6.6的振动寿命减少.
结论:
- 在AOT中位相中的分子动力学与非离子液体不同.
- 水分水平在调节当地环境和AOT结构内的动态方面发挥着作用.
- 这项研究提供了关于表面活性剂中相的结构演变和动态的见解.
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