The heterogeneous reaction of hydroxyl radicals with sub-micron squalane particles: a model system for understanding the oxidative aging of ambient aerosols
Smith, JD; Kroll, JH; Cappa, CD; Che, DL; Liu, CL; Ahmed, M; Leone, SR; Worsnop, DR; Wilson, KR
| HERO ID | 619765 |
|---|---|
| In Press | No |
| Year | 2009 |
| Title | The heterogeneous reaction of hydroxyl radicals with sub-micron squalane particles: a model system for understanding the oxidative aging of ambient aerosols |
| Authors | Smith, JD; Kroll, JH; Cappa, CD; Che, DL; Liu, CL; Ahmed, M; Leone, SR; Worsnop, DR; Wilson, KR |
| Journal | Atmospheric Chemistry and Physics |
| Volume | 9 |
| Issue | 9 |
| Page Numbers | 3209-3222 |
| Abstract | The heterogeneous reaction of OH radicals with sub-micron squalane particles, in the presence of O-2, 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 similar to 1 x 10(10) 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. |
| Doi | 10.5194/acp-9-3209-2009 |
| Wosid | WOS:000266189700021 |
| Is Certified Translation | No |
| Dupe Override | No |
| Comments | Source: Web of Science WOS:000266189700021 |
| Is Public | Yes |
| Keyword | Atmospheric pollution models; Organic aerosols in atmosphere; Atmospheric chemistry models; Atmospheric chemistry; Mass spectrometry; Hydroxyl photochemistry; Aerosols; Kinetics; Organic matter; Physicochemical properties; Troposphere; Particulates; Atmosphere; Hydroxyl radicals; aging; 2009) |
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