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| Titel |
Aqueous-phase oligomerization of methyl vinyl ketone through photooxidation – Part 1: Aging processes of oligomers |
| VerfasserIn |
P. Renard, F. Siekmann, G. Salque, C. Demelas, B. Coulomb, L. Vassalo, S. Ravier, B. Temime-Roussel, D. Voisin, A. Monod |
| 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 ; 15, no. 1 ; Nr. 15, no. 1 (2015-01-07), S.21-35 |
| Datensatznummer |
250119284
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| Publikation (Nr.) |
 copernicus.org/acp-15-21-2015.pdf |
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| Zusammenfassung |
| It has recently been established that unsaturated water-soluble organic
compounds (UWSOCs) might efficiently form oligomers in polluted fogs and wet
aerosol particles, even for weakly soluble ones like methyl vinyl ketone
(MVK). The atmospheric relevance of these processes is explored by means of
multiphase process model studies in a companion paper. In the present study,
we investigate the aging of these aqueous-phase MVK oligomers formed via
•OH oxidation, as well as their ability to form secondary
organic aerosol (SOA) upon water evaporation. The comparison between aqueous-phase composition and aerosol composition after nebulization of the
corresponding solutions shows similar trends for oligomer formation and
aging. The measurements reveal that oligomer aging leads to the formation of
organic diacids. Quantification of the SOA mass formed after nebulization is
performed, and the obtained SOA mass yields seem to depend on the spectral
irradiance of the light used to initiate the photochemistry. Investigating a
large range of initial MVK concentrations (0.2–20 mM), the results show
that their •OH oxidation undergoes competition between
functionalization and oligomerization that is dependent on the precursor
concentration. At high initial MVK concentrations (≥ 2 mM),
oligomerization prevails over functionalization, while at lower initial
concentrations, oligomerization is not the major process, and
functionalization dominates, resulting in small carbonyls, dicarbonyls and
monoacids. The atmospheric implications of these processes are discussed. |
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