HR: 11:35h
AN: A41G-05    [PDF]
TI: Aldol Condensation of Volatile Carbonyl Compounds in Acidic Aerosols
AU: Noziere, B
EM: bnoziere@rsmas.miami.edu
AF: Rosenstiel School for Marine and Atmospheric Science, Marine and Atmospheric Chemistry Division University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149 United States
AU: * Esteve, W
EM: westeve@rsmas.miami.edu
AF: Rosenstiel School for Marine and Atmospheric Science, Marine and Atmospheric Chemistry Division University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149 United States
AB: Reactions of volatile organic compounds in acidic aerosols have been shown recently to be potentially important for organic aerosol formation and growth. Aldol condensation, the acid-catalyzed polymerization of carbonyl compounds, is a likely candidate to enhance the flux of organic matter from the gas phase to the condensed phase in the atmosphere. Until now these reactions have only been characterized for conditions relevant to synthesis (high acidities and liquid phase systems) and remote from atmospheric ones. In this work, the uptake of gas-phase acetone and 2,4\-pentanedione by sulfuric acid solutions has been measured at room temperature using a Rotated Wetted Wall Reactor coupled to a Mass Spectrometer. The aldol condensation rate constants for 2,4\-pentanedione measured so far for sulfuric acid solutions between 96 and 70 % wt. display a variation with acidity in agreement with what predicted in the organic chemical literature. The values of these constants, however, are much lower than expected for this compound, and comparable to the ones of acetone. Experiments are underway to complete this study to lower acidities and understand the discrepancies with the predicted reactivity.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0317 Chemical kinetic and photochemical properties
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting