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| Titel |
The heterogeneous reaction of hydroxyl radicals with sub-micron squalane particles: a model system for understanding the oxidative aging of ambient aerosols |
| VerfasserIn |
J. D. Smith, J. H. Kroll, C. D. Cappa, D. L. Che, C. L. Liu, M. Ahmed, S. R. Leone, D. R. Worsnop, K. R. Wilson |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 9, no. 9 ; Nr. 9, no. 9 (2009-05-18), S.3209-3222 |
| Datensatznummer |
250007281
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| Publikation (Nr.) |
 copernicus.org/acp-9-3209-2009.pdf |
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| Zusammenfassung |
| The heterogeneous reaction of OH radicals with sub-micron squalane
particles, in the presence of O2, 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 ~1×1010 molecules cm−3. 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. |
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