| Autor: |
Hildebrandt Ruiz, L., Paciga, A. L., Cerully, K., Nenes, A., Donahue, N. M., Pandis, S. N. |
| Zdroj: |
Atmospheric Chemistry & Physics Discussions; 2014, Vol. 14 Issue 22, p31441-31481, 41p |
| Abstrakt: |
Secondary organic aerosol (SOA) is transformed after its initial formation, but this chemical aging of SOA is poorly understood. Experiments were conducted in the Carnegie Mellon environmental chamber to form and transform SOA from the photo-oxidation of toluene and other small aromatic volatile organic compounds (VOCs) in the presence of NOx. The effects of chemical aging on organic aerosol (OA) composition, mass yield, volatility and hygroscopicity were explored. Higher exposure to the hydroxyl radical resulted in different OA composition, average carbon oxidation state (...) and mass yield. The OA oxidation state generally increased during photo-oxidation, and the final OA ... ranged from -0.29 to 0.45 in the performed experiments. The volatility of OA formed in these different experiments varied by as much as a factor of 30, demonstrating that the OA formed under different oxidizing conditions can have significantly different saturation concentration. There was no clear correlation between hygroscopicity and oxidation state for this relatively hygroscopic SOA. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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