A new approach to determining gas-particle reaction probabilities and application to the heterogeneous reaction of deliquesced sodium chloride particles with gas-phase hydroxyl radicals.
J Phys Chem A
; 110(36): 10619-27, 2006 Sep 14.
Article
em En
| MEDLINE
| ID: mdl-16956244
ABSTRACT
The reaction kinetics for gaseous hydroxyl radicals (OH) with deliquesced sodium chloride particles (NaCl(aq)) were investigated using a novel experimental approach. The technique utilizes the exposure of substrate-deposited aerosol particles to reactive gases followed by chemical analysis of the particles using computer-controlled scanning electron microscopy with energy-dispersive analysis of X-rays (CCSEM/EDX) capability. Experiments were performed at room temperature and atmospheric pressure with deliquesced NaCl particles in the micron size range at 70-80% RH and with OH concentrations in the range of 1 to 7 x 10(9) cm(-3). The apparent, pseudo first-order rate constant for the reaction was determined from measurements of changes in the chloride concentration of individual particles upon reaction with OH as a function of the particle loading on the substrate. Quantitative treatment of the data using a model that incorporates both diffusion and reaction kinetics yields a lower limit to the net reaction probability of gamma(net) > or = 0.1, with an overall uncertainty of a factor of 2.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
J Phys Chem A
Assunto da revista:
QUIMICA
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Estados Unidos