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DOI | 10.5194/acp-17-8453-2017 |
Diffusivity measurements of volatile organics in levitated viscous aerosol particles | |
Bastelberger, Sandra; Krieger, Ulrich K.; Luo, Beiping; Peter, Thomas | |
2017-07-11 | |
发表期刊 | ATMOSPHERIC CHEMISTRY AND PHYSICS
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ISSN | 1680-7316 |
EISSN | 1680-7324 |
出版年 | 2017 |
卷号 | 17期号:13 |
文章类型 | Article |
语种 | 英语 |
国家 | Switzerland |
英文摘要 | Field measurements indicating that atmospheric secondary organic aerosol (SOA) particles can be present in a highly viscous, glassy state have spurred numerous studies addressing low diffusivities of water in glassy aerosols. The focus of these studies is on kinetic limitations of hygro-scopic growth and the plasticizing effect of water. In contrast, much less is known about diffusion limitations of organic molecules and oxidants in viscous matrices. These may affect atmospheric chemistry and gas-particle partitioning of complex mixtures with constituents of different volatility. In this study, we quantify the diffusivity of a volatile organic in a viscous matrix. Evaporation of single particles generated from an aqueous solution of sucrose and small amounts of volatile tetraethylene glycol (PEG-4) is investigated in an electrodynamic balance at controlled relative humidity (RH) and temperature. The evaporative loss of PEG-4 as determined by Mie resonance spectroscopy is used in conjunction with a radially resolved diffusion model to retrieve translational diffusion coefficients of PEG-4. Comparison of the experimentally derived diffusivities with viscosity estimates for the ternary system reveals a breakdown of the Stokes-Einstein relationship, which has often been invoked to infer diffusivity from viscosity. The evaporation of PEG-4 shows pronounced RH and temperature dependencies and is severely depressed for RH less than or similar to 30 %, corresponding to diffusivities < 10(-14) cm(2) s(-1) at temperatures < 15 degrees C. The temperature dependence is strong, suggesting a diffusion activation energy of about 300 kJ mol(-1). We conclude that atmospheric volatile organic compounds can be subject to severe diffusion limitations in viscous organic aerosol particles. This may enable an important long-range transport mechanism for organic material, including pollutant molecules such as polycyclic aromatic hydrocarbons (PAHs). |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000405372800005 |
WOS关键词 | POLYCYCLIC AROMATIC-HYDROCARBONS ; LONG-RANGE TRANSPORT ; PARTIAL MOLAR VOLUMES ; AQUEOUS-SOLUTIONS ; WATER DIFFUSION ; VAPOR-PRESSURES ; TRANSLATIONAL DIFFUSION ; RESONANCE SPECTROSCOPY ; ACTIVITY-COEFFICIENTS ; CHEMICAL-REACTIVITY |
WOS类目 | Environmental Sciences ; Meteorology & Atmospheric Sciences |
WOS研究方向 | Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/20608 |
专题 | 地球科学 |
作者单位 | ETH, Inst Atmospher & Climate Sci, CH-8092 Zurich, Switzerland |
推荐引用方式 GB/T 7714 | Bastelberger, Sandra,Krieger, Ulrich K.,Luo, Beiping,et al. Diffusivity measurements of volatile organics in levitated viscous aerosol particles[J]. ATMOSPHERIC CHEMISTRY AND PHYSICS,2017,17(13). |
APA | Bastelberger, Sandra,Krieger, Ulrich K.,Luo, Beiping,&Peter, Thomas.(2017).Diffusivity measurements of volatile organics in levitated viscous aerosol particles.ATMOSPHERIC CHEMISTRY AND PHYSICS,17(13). |
MLA | Bastelberger, Sandra,et al."Diffusivity measurements of volatile organics in levitated viscous aerosol particles".ATMOSPHERIC CHEMISTRY AND PHYSICS 17.13(2017). |
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