Probing the Equilibrium Size and Hydrogen Bonding Structure in Aqueous Aerosol Droplets
Probing the Equilibrium Size and Hydrogen Bonding Structure in Aqueous Aerosol Droplets
复制标题
DOI：
10.1524/zpch.2010.6147
复制
发表时间：
2010-08
期刊：
影响因子：
--
通讯作者：
L. Treuel;J. Butler;G. Hargreaves;J. Reid
中科院分区：
文献类型：
--
作者：
L. Treuel;J. Butler;G. Hargreaves;J. Reid
摘要对两个或多个光学捕获的气溶胶液滴进行比较测量，可以对气溶胶的吸湿特性进行细致的研究。在本文中，我们考虑两种方法来评估的相对湿度的水活度和溶质浓度在凝聚相的依赖。我们证明，在本文中，使用控制液滴作为微探针的相对湿度在附近的第二个液滴的利益可以允许的RH被确定与0.01至0.1%之间的精度。不仅是这样的探头高度响应，但RH测定的准确性提高与GF或RH的增加，对宏观RH探头的性能。我们还表明，自发的拉曼散射记录从激发的OH伸缩振动在过饱和溶液的氯化钠液滴显示了相当大的扰动引起的氯离子的氢键网络。氯化物被认为是一种氢键结构破坏剂，这些观察结果与更稀溶液的测量结果一致。
Abstract Comparative measurements on two or more optically trapped aerosol droplets can allow the hygroscopic properties of aerosol to be investigated in exquisite detail. In this paper we consider two methods for assessing the dependence on relative humidity of the water activity and solute concentration in the condensed phase. We demonstrate in this paper that using a control droplet as a microprobe of relative humidity in the vicinity of a second droplet of interest can allow the RH to be determined with an accuracy of between 0.01 to 0.1 %. Not only is such a probe highly responsive, but the accuracy of the RH determination improves with increase in GF or RH, counter to the performance of macroscopic RH probes. We also demonstrate that spontaneous Raman scattering recorded from excitation of the OH stretching vibration in supersaturated solution droplets of sodium chloride shows the considerable perturbation induced by the chloride ion on the hydrogen bonding network. Chloride is recognised as a hydrogen bonding structure breaker and these observations are shown to be consistent with measurements on more dilute solutions.