Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 14, 10731-10740, 2014
https://doi.org/10.5194/acp-14-10731-2014
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
10 Oct 2014
Climate-relevant physical properties of molecular constituents for isoprene-derived secondary organic aerosol material
M. A. Upshur1, B. F. Strick1, V. F. McNeill2, R. J. Thomson1, and F. M. Geiger1 1Department of Chemistry, Northwestern University, Evanston, IL 60202, USA
2Department of Chemical Engineering, Columbia University, New York, NY 10027, USA
Abstract. Secondary organic aerosol (SOA) particles, formed from gas-phase biogenic volatile organic compounds (BVOCs), contribute large uncertainties to the radiative forcing that is associated with aerosols in the climate system. Reactive uptake of surface-active organic oxidation products of BVOCs at the gas–aerosol interface can potentially decrease the overall aerosol surface tension and therefore influence their propensity to act as cloud condensation nuclei (CCN). Here, we synthesize and measure some climate-relevant physical properties of SOA particle constituents consisting of the isoprene oxidation products α-, δ-, and cis- and trans-β-IEPOX (isoprene epoxide), as well as syn- and anti-2-methyltetraol. Following viscosity measurements, we use octanol–water partition coefficients to quantify the relative hydrophobicity of the oxidation products while dynamic surface tension measurements indicate that aqueous solutions of α- and trans-β-IEPOX exhibit significant surface tension depression. We hypothesize that the surface activity of these compounds may enhance aerosol CCN activity, and that trans-β-IEPOX may be highly relevant for surface chemistry of aerosol particles relative to other IEPOX isomers.

Citation: Upshur, M. A., Strick, B. F., McNeill, V. F., Thomson, R. J., and Geiger, F. M.: Climate-relevant physical properties of molecular constituents for isoprene-derived secondary organic aerosol material, Atmos. Chem. Phys., 14, 10731-10740, https://doi.org/10.5194/acp-14-10731-2014, 2014.
Publications Copernicus
Download
Share