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Title: Effect of surface–bulk partitioning on the heterogeneous oxidation of aqueous saccharide aerosols
The OH-initiated heterogeneous oxidation of mixed saccharide aqueous aerosols is investigated using an atmospheric-pressure flow tube coupled to off-line analysis of the particle composition. For equimolar monosaccharide/disaccharide aqueous aerosol mixtures, the decay of the disaccharide is found to be significantly slower than that of the monosaccharide. Molecular dynamics simulations of the mixed aqueous solutions reveal the formation of a ∼10 Å disaccharide exclusion layer below the water surface. A simple chemical model is developed to discuss the possible effect of the disaccharide surface partitioning on the heterogeneous kinetics. The observed decays are consistent with a poor spatial overlap of the OH radical at the interface with the disaccharide in the particle bulk. The effect of partitioning on the heterogeneous oxidation of atmospheric organic aerosols is discussed.  more » « less
Award ID(s):
1726534
PAR ID:
10196966
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
Physical Chemistry Chemical Physics
Volume:
21
Issue:
6
ISSN:
1463-9076
Page Range / eLocation ID:
2992 to 3001
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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