AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Constraining Organic Aerosol Volatility from Evaporation Rate Measurements from Thermodenuders
JAMES HITE, Rebecca Schwantes, Kelvin Bates, Tran Nguyen, Richard Flagan, John Seinfeld, Athanasios Nenes, Georgia Institute of Technology
Abstract Number: 510 Working Group: Aerosol Chemistry
Abstract Thermodeunders (TD) are commonly used now in laboratory and ambient studies of aerosols to provide information about organic aerosol volatility. Experiments involving thermodenuder observations tend to conflate the aerosol evaporation rate with the thermodynamic driving force – volatility – without adequately constraining the kinetic limitations of the mass transfer, namely the mass accommodation coefficient (α). In light of more recent developments in research concerning secondary organic aerosol (SOA), the likelihood that SOA can exhibit characteristics that would act as kinetic limitations to volatilization (α < 1) presents a challenge for the interpretation of data collected with TDs and demonstrates the need for experimental methods and analysis techniques to constrain this critical unknown.
Laboratory results for dicarboxylic acid aerosol generated from aqueous solution via atomization using the GT TD system and variable pressure technique will be presented. Parameter optimization from minimal data will be discussed to demonstrate this method’s feasibility for ambient, high-temporal, and thus potentially airborne retrieval of aerosol volatility. Select data from environmental chamber SOA experiments sampled with this system will also be presented, making use of the volatility basis set (VBS) approach.