American Association for Aerosol Research - Abstract Submission

AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA

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Novel Experiments Give Quantitative Measure of Atmospheric Particle Viscosities

LINDSAY RENBAUM-WOLFF, Allan Bertram, Adam Bateman, Mikinori Kuwata, Scot Martin, University of British Columbia

     Abstract Number: 492
     Working Group: Aerosol Chemistry

Abstract
Until recently it was assumed that atmospheric secondary organic aerosol (SOA) is liquid and bulk diffusion is fast and the models used to describe the formation of SOA in the atmosphere were developed based on this assumption. However, recent evidence suggests SOA particles may form amorphous solid or semisolid states under some conditions. While these recent experiments have provided qualitative evidence that SOA may be solid or semi-solid under some conditions, quantitative measures of the rate of bulk diffusion or the dynamic viscosity are needed in order to understand the atmospheric implications and to accurately model SOA processes. The small sample volumes associated with SOA collection present a major obstacle in quantifying particle viscosities. Here we describe a straight-forward method for the quantification of particle viscosities at various relative humidities with implications for atmospheric models and atmospheric processes.