AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Interfacial Chemistry and Cloud Activation in Organic Aerosol
JAMES F. DAVIES, Chris Ruehl, Kevin Wilson, Lawrence Berkeley National Laboratory
Abstract Number: 485 Working Group: Aerosol Chemistry
Abstract The molecular composition at the surface of airborne particles plays an important role in regulating the chemical and physical dynamics of aerosol. In viscous particles, where molecular transport is limited by slow diffusion, chemistry occurring at the surface can lead to steep interfacial gradients (1). In mixed component particles, phase separation and surface partitioning can influence the cloud activation mechanism, with surface tension playing an important role in regulating the size of droplets approaching the point of activation (2).
In this work, we detail a selection of our laboratory-based studies exploring molecular transport dynamics and chemical kinetics, demonstrating the complex physical chemistry associated with the dynamics of atmospheric aerosol. In particular, we focus on the role of organic species in aerosol, which perturb both viscosity and surface tension. Using a combination of flow-tube methods and single-particle traps, we explore how these properties influence chemical processing, molecular diffusion and cloud activation.
(1) Davies, J. F.; Wilson, K. R. Nanoscale Interfacial Gradients Formed by the Reactive Uptake of OH Radicals onto Viscous Aerosol Surfaces. Chem. Sci. 2015, 6, 7020–7027.
(2) Ruehl, C. R.; Davies, J. F.; Wilson, K. R. An interfacial mechanism for cloud droplet formation on organic aerosols. Science. 2016, 351, 1447-1450.