Measurements of the Equilibrium Size of Supersaturated Aqueous Sodium Chloride Droplets at Low Relative Humidity Using Aerosol Optical Tweezers and an Electrodynamic Balance
Measurements of the Equilibrium Size of Supersaturated Aqueous Sodium Chloride Droplets at Low Relative Humidity Using Aerosol Optical Tweezers and an Electrodynamic Balance
复制标题
使用气溶胶光学镊子和电动天平测量低相对湿度下过饱和氯化钠水溶液液滴的平衡尺寸
DOI：
10.1021/jp9095985
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发表时间：
2010-02-04
影响因子：
2.9
通讯作者：
Reid, J. P.
中科院分区：
文献类型：
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作者：
Hargreaves, G.;Kwamena, N. -O. A.;Reid, J. P.
提出了一种利用气溶胶光学镊子在较宽的相对湿度范围内检测单个气溶胶颗粒吸湿性的方法，并与使用电动天平进行的测量进行了比较。尤其是。基准测量是在RH范围45-75%(293K)的油水溶液氯化钠气溶胶，这一RH范围以前从未用气溶胶光学镊子探测过。利用腔增强拉曼散射测量了平衡湿液滴尺寸随相对湿度的变化。在湿颗粒半径的测定中，所有精度均为1 nm。将全系列光钳实验测量结果(包括先前接近饱和相对湿度100%的双捕获对比研究)与使用其他实验技术和一系列模型处理的测定结果进行了比较。对用于估计氯化钠液滴平衡尺寸的模型和所有实验数据的评估表明，在相对湿度为48-100%的范围内，可以以优于0.1%的所有精度预测氯化钠液滴的尺寸。当接近开花时，不同测量之间的差异会导致所有RH低于48%的1%以上的不确定度增加。光钳对平衡尺寸的测量与模型预测一致，误差在1%以内(
An approach for examining the hygroscopicity of single aerosol particles over I broad range in relative humidity (RH) using aerosol optical tweezers is presented and compared with measurements made using an electrodynamic balance. In particular. benchmark measurements oil aqueous sodium chloride aerosol are presented over the RH range 45-75% (293 K), a RH range that had not previously been explored with aerosol optical tweezers. Measurements of the variation in equilibrium wet droplet size with RH are made using cavity-enhanced Raman scattering. with all accuracy of 1 nm in the determination of the wet particle radius. The Full range of optical tweezers experimental measurements (including previous dual trapping comparative studies approaching a saturation relative humidity of 100%) are compared with determinations using other experimental techniques and with a range of model treatments. An assessment of the models and all experimental data for estimating the equilibrium size of a sodium chloride droplet suggests that the size can be predicted with all accuracy of better than 0.1% over the RH range 48-100%. Discrepancies between different measurements lead to all increase ill uncertainty above 1% below all RH of 48% as efflorescence is approached. The optical tweezers' measurements of equilibrium size consistently agree with model predictions to within an error of 1% (