HR: 0800h
AN: A51E-0826    [Abstracts]
TI: Permeability of Organic Films at the Air-Aqueous Interface
AU: * Gilman, J B
EM: jessica.gilman@colorado.edu
AF: University of Colorado, Boulder, Dept of Chemistry and Biochemistry Campus Box 215, Boulder, CO 80309
AU: Vaida, V
EM: vaida@colorado.edu
AF: University of Colorado, Boulder, Dept of Chemistry and Biochemistry Campus Box 215, Boulder, CO 80309
AB: Organics represent a significant percentage of the composition of atmospheric aerosols. It has been determined in recent field studies that amphiphilic organics, such as fatty acids, are a large constituent of the organic fraction. Fatty acids have the unique ability to partition to and remain at the air-aqueous interface. Their presence at the interface alters many interesting physical, chemical, and morphological properties that are discussed. In this set of experiments, we address the permeability of gaseous molecules, either water or small organics, across the hydrophobic barrier created by a fatty acid monolayer. The evaporation rate of the organically coated water subphase is investigated as a function of the fatty acid carbon number, from C12 to C24. Subsequently, the permeability of the hydrocarbon barrier to small organics is monitored. The relevance of these findings as they relate to the properties of organic aerosols as well as recent surface-sensitive aerosol field measurements is discussed.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0399 General or miscellaneous
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting