AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Nanoparticle Growth Measurements in a Flow Tube Reactor
MURRAY JOHNSTON, Chris Stangl, Justin Krasnomowitz, Andrew J. Horan, Michael Apsokardu, University of Delaware
Abstract Number: 169 Working Group: Aerosol Chemistry
Abstract New particle formation (NPF) is observed around the world and is thought to contribute substantially to the concentration of cloud condensation nuclei (CCN). Newly formed particles must grow quickly if they are to reach the relevant size range to serve as CCN. In order to better predict the frequency, growth rates, and climatic impacts of NPF, knowledge of the chemical mechanisms by which nucleated nanoparticles grow is needed. We have constructed and tested a flow tube reactor that allows reactant concentrations and reaction times to be systematically varied. The reaction time can be as long as ~40 min, making it possible to investigate processes with atmospherically relevant growth rates approaching 10 nm/hr for 10 nm dia. particles. Initial experiments are focused on distinguishing the contributions of sulfuric acid and oxidized organics to particle growth using chemical composition measurements with the nano aerosol mass spectrometer (NAMS). The experimental approach allows the organic molecular growth rate to be quantified though comparison with condensational growth by sulfuric acid. These experiments and initial results will be presented.