Morphological effects on coated aerosol kinetics

Morphological effects on coated aerosol kinetics Public Deposited

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Rosen, Elias Patrick
- Affiliation: College of Arts and Sciences, Department of Chemistry

Abstract

Single-particle kinetic studies of the reaction between oleic acid and O3 have been conducted on two different types of core particles: polystyrene latex and silica. Oleic acid was found to adsorb to both particle types in multilayer islands that resulted in a surfactant layer of a total volume estimated to be less than one monolayer. The rate of the surface reaction between surface-adsorbed oleic acid and O3 has been shown for the first time to be influenced by the composition of the aerosol substrate in a mixed organic/inorganic particle. The reaction on the hydrophobic polystyrene core proceeded more efficiently than on a silica core at lower [O3], and the observed dependence of the observed pseudo-first order rate constant with [O3] suggests that the reaction is more efficient on the silica surface, but proceeds faster on the less polar PSL core at lower [O3] due to the increased residence time of O3 on the PSL surface. Values for the uptake coefficient, [gamma]oleic, for reaction of oleic acid on polystyrene latex spheres decrease from 2.5 x 10-5 to 1 x 10-5 with increasing [O3] from 4 to 25 ppm and overlap at high [O3] with the estimated values for [gamma]oleic on silica, which decrease from 1.6 x 10-5 to 1.3 x 10-5.

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