...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical chemistry chemical physics: PCCP >Surface behavior of amphiphiles in aqueous solution: a comparison between different pentanol isomers
【24h】

Surface behavior of amphiphiles in aqueous solution: a comparison between different pentanol isomers

机译：两亲物在水溶液中的表面行为：不同戊醇异构体之间的比较

获取原文
获取原文并翻译 | 示例
   

获取外文期刊封面封底 >>

       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Position isomerism is ubiquitous in atmospheric oxidation reactions. Therefore, we have compared surface-active oxygenated amphiphilic isomers (1- and 3-pentanol) at the aqueous surface with surface- and chemically sensitive X-ray photoelectron spectroscopy (XPS), which reveals information about the surface structure on a molecular level. The experimental data are complemented with molecular dynamics (MD) simulations. A concentration-dependent orientation and solvation of the amphiphiles at the aqueous surface is observed. At bulk concentrations as low as around 100 mM, a monolayer starts to form for both isomers, with the hydroxyl groups pointing towards the bulk water and the alkyl chains pointing towards the vacuum. The monolayer (ML) packing density of 3-pentanol is approx. 70% of the one observed for 1-pentanol, with a molar surface concentration that is approx. 90 times higher than the bulk concentration for both molecules. The molecular area at ML coverage (approximate to 100 mM) was calculated to be around 32 +/- 2 angstrom(2) per molecule for 1-pentanol and around 46 +/- 2 angstrom(2) per molecule for 3-pentanol, which results in a higher surface concentration (molecules per cm(2)) for the linear isomer. In general we conclude therefore that isomers - with comparable surface activities - that have smaller molecular areas will be more abundant at the interface in comparison to isomers with larger molecular areas, which might be of crucial importance for the understanding of key properties of aerosols, such as evaporation and uptake capabilities as well as their reactivity.
机译：位置异构在大气氧化反应中无处不在。因此，我们将水表面的表面活性氧化两亲异构体（1-和3-戊醇）与对表面和化学敏感的X射线光电子能谱（XPS）进行了比较，从而揭示了在分子水平上有关表面结构的信息。实验数据辅以分子动力学（MD）模拟。观察到两亲物在水表面的浓度依赖性取向和溶剂化。在低至约100 mM的堆积浓度下，两种异构体均开始形成单层，其中羟基指向大量水，​​烷基链指向真空。 3-戊醇的单层（ML）堆积密度约为1。观察到的1-戊醇的70％，其摩尔表面浓度约为比两个分子的体积浓度高90倍。 ML覆盖下的分子面积（大约100 mM）对于1-戊醇约为每分子32 +/- 2埃（2），对于3-戊醇约为每分子46 +/- 2埃（2），导致线性异构体的表面浓度更高（每厘米分子数（2）的分子）。因此，总的来说，我们得出的结论是，与具有较大表面面积的异构体相比，具有较小表面面积的异构体与具有较大表面面积的异构体相比，在界面处的富集度更高，这对于理解气溶胶的关键特性至关重要，例如蒸发和吸收能力以及它们的反应性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号