Reactive Uptake of Ozone by Oleic Acid Aerosol Particles: Application of Single-Particle Mass Spectrometry to Heterogeneous Reaction Kinetics
| Autor: | Cindy L. DeForest, Ephraim Woods, Roger E. Miller, Tomas Baer, Geoffrey D. Smith |
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| Rok vydání: | 2002 |
| Předmět: | |
| Zdroj: | The Journal of Physical Chemistry A. 106:8085-8095 |
| ISSN: | 1520-5215 1089-5639 |
| DOI: | 10.1021/jp020527t |
| Popis: | The technique of single-particle mass spectrometry has been coupled to a reaction flow tube to measure the uptake coefficient, γ, of ozone (O3) by oleic acid (9-octadecenoic acid) aerosol particles. The reaction was followed by monitoring the decrease of oleic acid in the size-selected particles as a function of O3 exposure. The reactive uptake coefficient is found to depend on the size of the particle, with γmeas ranging from (7.3 ± 1.5) × 10-3 to (0.99 ± 0.09) × 10-3 for particles ranging in radius from 680 nm to 2.45 μm. It is suggested that the decrease in γmeas with increasing particle size results from the reaction being limited by the diffusion of oleic acid within the particle, and based on our measurements we estimate the value of γ to be (5.8−9.8) × 10-3 for particles that are not limited by oleic acid diffusion. A reaction model that includes simultaneous diffusion and reaction of both O3 and oleic acid is developed and used to fit the observed rates of reaction. Solutions obtained from this mo... |
| Databáze: | OpenAIRE |
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