Surface tension of single suspended aerosol microdroplets  

作　　者：Yukai Tong Zhijun Wu Bo Zhou Min Hu Anpei Ye 

机构地区：[1]Key Laboratory for the Physics and Chemistry of Nanodevices,School of Electronics,Peking University,Beijing 100871,China [2]State Key Joint Laboratory of Environmental Simulation and Pollution Control,College of Environmental Sciences and Engineering,Peking University,Beijing 100871,China [3]Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100094,China

出　　处：《Chinese Chemical Letters》2024年第4期520-524,共5页中国化学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China (Nos.U19A2007, 32150026 and 92043302)。

摘　　要：The surface tension of troposphere aerosols can significantly influence their atmospheric processes and key properties, particularly on the morphology, the phase transition, the activation as cloud condensation nuclei, and the gas-particle partitioning. However, directly measuring the surface tension of single ambient aerosol is quite challenging, due to the limitations of their picolitre volumes and thermal motion. Here, we developed a dual laser tweezers Raman spectroscopy(DLT-RS) system to directly sense the surface tension of single airborne microdroplets(PM10particles). A pair of aerosol droplets were trapped and driven to coalesce by the laser tweezers. Meanwhile, the backscattering light intensity and brightfield images during the coalescence process were recorded to characterize the aerosol surface tension. A remarkable advantage of directly sensing aerosol surface tension is that the solutes in aerosols are often supersaturated, which is common in atmospheric aerosols but almost unavailable in bulk solutions.We experimentally measured the surface tension of aerosols composed of nitrates or oxalic acid/nitrate mixture. Besides, the variation of surface tension during aerosol aging process was also explored, which brings possible implications on the surface evolution of actual ambient aerosol during their atmospheric lifetime.

关 键 词：Surface tension Droplet coalescence Single aerosol Laser tweezers Aerosol aging 

分 类 号：O648.18[理学—物理化学]