Organic films at the air-water interface as models for atmospheric organic aerosols

COLL 279

Veronica Vaida, vaida@colorado.edu, Department of Chemistry and Biochemistry, University of Colorado at Boulder, Campus Box 215, Boulder, CO 80309-215
Water-air interfaces as found at the sea surface and on atmospheric aerosols provide unique reaction environments. Organic monolayers on water in the environment are exposed both to an aqueous phase containing dissolved inorganic and organic species and to the atmosphere containing reactive radicals and solar photons.

The focus of this presentation is on the morphology, stability and permeability of organic films on aqueous solutions chosen to mimic atmospheric aerosols. Both single and multicomponent films of organic acids, alcohols and their fluorinated counterparts are investigated in Langmuir-Blodgett trough experiments. The results point to the effects of such surfactant films in determining the aerosol's properties and composition. Laboratory studies are compared with results of field measurements. Implications of these laboratory results in understanding chemical, physical and optical properties of organic atmospheric aerosols will be discussed.