自组装内部的暴露于外部元素. 一种动力学方法
1Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA. menger@emory.edu
Journal of the American Chemical Society
|July 20, 2006
概括
表面活性剂吸附到微粒中显著减缓了硫链的周期性氧化,但不能减缓过氧化的氧化. 这表明,无序的小为所有链条位置提供了类似的进入小表面的机会.
科学领域:
- 物理化学 物理化学
- 超分子化学 超分子化学
- 化学动力学 化学动力学
背景情况:
- 表面活性物自组装成,在溶液中形成有组织的结构.
- 了解微粒中表面活性分子不同部分的可访问性对于预测它们的反应性至关重要.
研究的目的:
- 为了研究菌形成对含有铁的阴离子表面活性剂的氧化率的影响.
- 为了确定硫原子在表面活性剂链中的位置是否会影响其在微粒中的氧化剂的可访问性.
主要方法:
- 具有不同硫位的阴离子表面活性剂吸附到二甲基硫酸盐微粒中.
- 使用周期酸盐和过氧化作为氧化剂,对乙烯氧化作用的动态分析.
- 核磁共振 (NMR) 光谱法用于确定反应速度.
主要成果:
- 周期性氧化率在化时减少了两倍,不管硫原子的位置如何.
- 过氧化的氧化率受到微粒形成的最小影响.
- 对于任何一种氧化剂,都没有观察到氧化率与表面活性剂链内的硫位置的显著依赖.
结论:
- 菌体的形成导致了一个无序的结构,所有链条位置都对外部环境具有相似的可访问性.
- 使用NMR的动态方法是一种可行的方法,可以探测自我组装和聚合物系统中分子的可访问性.
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