10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
In-situ Surface Tension Measurements of Hanging Droplet Aerosol Mimics under Photooxidative Conditions
Thomas Beier, JOSEPH WOO, Lafayette College
Abstract Number: 981 Working Group: Aerosol Chemistry
Abstract Oligomeric products of carbonyl-containing volatile organic compounds (CVOCs) have been shown to exhibit surface-active properties in aqueous aerosols, affecting their contributions to indirect radiative forcing effects on the atmosphere. These aerosol-phase oligomeric products are also known to exhibit compositional changes due to photobleaching in UV-irradiated environments. The relative rates of formation and effects of these oxidized compounds may be enhanced in aerosol conditions compared to in bulk phase due to their relatively high surface area, where these surface-active substances are thought to partition. In this study, surface tension and UV/Vis spectrographical data is collected for small (<20uL) hanging-drop aqueous aerosol mimics, which are exposed to controlled gas-phase CVOCs and UV radiation. These droplets act as an intermediate size scale between bulk mimic and aerosol-chamber studies, allowing for direct individual droplet measurement while maintaining a relatively high surface-volume ratio for heterogeneous photochemistry to occur. Observed surface tension and absorbance measurements are compared to Syszkowski-Langmuir and bulk-phase absorbance estimations (respectively) using GAMMA, a 0-dimensional computational box model.