The heterogeneous reaction of hydroxyl radicals with sub-micron squalane particles: a model system for understanding the oxidative aging of ambient aerosols
Item
Title (Dublin Core)
The heterogeneous reaction of hydroxyl radicals with sub-micron squalane particles: a model system for understanding the oxidative aging of ambient aerosols
Description (Dublin Core)
The heterogeneous reaction of OH radicals with sub-micron squalane particles, in the presence of O<sub>2</sub>, is used as a model system to explore the fundamental chemical mechanisms that control the oxidative aging of organic aerosols in the atmosphere. Detailed kinetic measurements combined with elemental mass spectrometric analysis reveal that the reaction proceeds sequentially by adding an average of one oxygenated functional group per reactive loss of squalane. The reactive uptake coefficient of OH with squalane particles is determined to be 0.3±0.07 at an average OH concentration of ~1×10<sup>10</sup> molecules cm<sup>−3</sup>. Based on a comparison between the measured particle mass and model predictions it appears that significant volatilization of a reduced organic particle would be extremely slow in the real atmosphere. However, as the aerosols become more oxygenated, volatilization becomes a significant loss channel for organic material in the particle-phase. Together these results provide a chemical framework in which to understand how heterogeneous chemistry transforms the physiochemical properties of particle-phase organic matter in the troposphere.
Creator (Dublin Core)
Smith, J. D.
Kroll, J. H.
Cappa, C. D.
Che, D. L.
Liu, C. L.
Ahmed, M.
Leone, S. R.
Worsnop, D. R.
Wilson, K. R.
Date (Dublin Core)
2018-01-15
Type (Dublin Core)
Text
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
10.5194/acp-9-3209-2009
https://acp.copernicus.org/articles/9/3209/2009/
Source (Dublin Core)
eISSN: 1680-7324
Language (Dublin Core)
eng
