COLL 282 |
| Internal mixtures of inorganic and organic material are typical of tropospheric aerosols, and surface-active organics are a common component of the organic fraction. Surface-active molecules may partition to the gas-aerosol interface of aqueous particles, lowering the surface tension and creating an organic surface layer. We have shown that submonolayer films of expanded-state surfactants can significantly suppress the reactive uptake of N2O5 by submicron aqueous aerosols. We also used aerosol flow tube reactors with chemical ionization mass spectrometry detection of the gas and particle phases in order to assess the lifetimes of such films when subject to oxidation by O3 and OH in the atmosphere, along with the gas-particle partitioning of the oxidation products. Finally, we will discuss results from recent ellipsometry studies of the surface-bulk partitioning of organic material in systems approaching the complexity of internally mixed aerosols in the atmosphere. |
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The Physical Chemistry of Environmental Interfaces
9:00 AM-1:10 PM, Tuesday, April 8, 2008 Morial Convention Center -- Rm. 225, Oral
Division of Colloid & Surface Chemistry |