Abstract View
Influence of Structure and Functionality on Uptake of Semivolatile Organic Compounds to Surfaces
GRAHAM FRAZIER, Gabriel Isaacman-VanWertz, John Morris, Virginia Tech
Abstract Number: 282
Working Group: Aerosol Chemistry
Abstract
Mineral compounds, both on the ground and suspended as aerosols, present unique surfaces for deposition and chemical reactions of reactive organic gases. To date, the many of uptake studies have focused on inorganic species and oxidation studies. However, most organic carbon is emitted to the atmosphere as reduced carbon from a small subset of terpenoid compound classes. Many of these compounds are semivolatile, and even the more volatiles compound classes (e.g., monoterpenes) have been shown to reversibly partition to surfaces under typical ambient conditions. Small differences in the molecular structures of organic compounds can have substantial impacts on their physicochemical properties, so it is critical to understand the role of molecular structure on the uptake and surface chemistry of reactive organic compounds. We explore the influence of structure by measure surface uptake and interactions for a range of benzyl substituted compounds with systematically varied functionality, including aromatic monoterpenes. Uptake is measured on several compounds chosen to represent a selection of environmentally relevant surfaces by flowing sub-ppb concentrations through a flow tube with varied lengths of coated material. In addition, key interactions responsible for surface uptake were interrogated via transmission infrared spectroscopy. Together, these techniques provide new insights into the role of adsorbate electronegativity, molecular structure, and acid-base interactions on the uptake of organic compounds by environmentally relevant surfaces.