Secondary Organic Aerosol Formation from Cyclohexene Ozonolysis: Effect of OH Scavenger and the Role of Radical Chemistry

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• 作者：M. D. Keywood ; J. H. Kroll ; V. Varutbangkul ; R. Bahreini ; R. C. Flagan ; and J. H. Seinfeld
• 刊名：Environmental Science & Technology
• 出版年：2004
• 出版时间：June 15, 2004
• 年：2004
• 卷：38
• 期：12
• 页码：3343 - 3350
• 全文大小：168K
• 年卷期：v.38,no.12(June 15, 2004)
• ISSN：1520-5851

文摘

To isolate secondary organic aerosol (SOA) formation inozone-alkene systems from the additional influence of hydroxyl(OH) radicals formed in the gas-phase ozone-alkenereaction, OH scavengers are employed. The detailedchemistry associated with three different scavengers(cyclohexane, 2-butanol, and CO) is studied in relation tothe effects of the scavengers on observed SOA yields in theozone-cyclohexene system. Our results confirm those ofDocherty and Ziemann that the OH scavenger plays a rolein SOA formation in alkene ozonolysis. The extent anddirection of this influence are shown to be dependent onthe specific alkene. The main influence of the scavengerarises from its independent production of HO₂ radicals, withCO producing the most HO₂, 2-butanol an intermediateamount, and cyclohexane the least. This work providesevidence for the central role of acylperoxy radicals in SOAformation from the ozonolysis of alkenes and generallyunderscores the importance of gas-phase radical chemistrybeyond the initial ozone-alkene reaction.