Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published November 15, 2013 | Supplemental Material + Published
Journal Article Open

Effect of chemical structure on secondary organic aerosol formation from C_(12) alkanes


The secondary organic aerosol (SOA) formation from four C_(12) alkanes (n-dodecane, 2-methylundecane, hexylcyclohexane, and cyclododecane) is studied in the Caltech Environmental Chamber under low-NO_x conditions, in which the principal fate of the peroxy radical formed in the initial OH reaction is reaction with HO_2. Simultaneous gas- and particle-phase measurements elucidate the effect of alkane structure on the chemical mechanisms underlying SOA growth. Reaction of branched structures leads to fragmentation and more volatile products, while cyclic structures are subject to faster oxidation and lead to less volatile products. Product identifications reveal that particle-phase reactions involving peroxyhemiacetal formation from several multifunctional hydroperoxide species are key components of initial SOA growth in all four systems. The continued chemical evolution of the particle-phase is structure-dependent, with 2-methylundecane SOA formation exhibiting the least extent of chemical processing and cyclododecane SOA achieving sustained growth with the greatest variety of chemical pathways. The extent of chemical development is not necessarily reflected in the oxygen to carbon (O : C) ratio of the aerosol as cyclododecane achieves the lowest O : C, just above 0.2, by the end of the experiment and hexylcyclohexane the highest, approaching 0.35.

Additional Information

© 2013 Author(s). This work is distributed under the Creative Commons Attribution 3.0 License. Published by Copernicus Publications on behalf of the European Geosciences Union. Received: 5 April 2013. Published in Atmos. Chem. Phys. Discuss.: 24 April 2013. Revised: 17 September 2013. Accepted: 11 October 2013. Published: 15 November 2013. This work was supported by the Office of Science (Biological and Environmental Research), US Department of Energy Grant (DE-SC 0006626), and National Science Foundation Grants AGS-1057183 and ATM-0650061. The authors acknowledge helpful discussions with John D. Crounse and Jason M. St. Clair regarding treatment of CIMS data and gas-phase data, as well as experimental assistance and discussions with Reddy L. N. Yatavelli and ManNin Chan. L. D. Yee, J. S. Craven, and C. L. Loza were supported by National Science Foundation Graduate Research Fellowships. Edited by: J. Liggio

Attached Files

Published - acp-13-11121-2013.pdf

Supplemental Material - acp-13-11121-2013-supplement.pdf


Files (1.3 MB)
Name Size Download all
599.9 kB Preview Download
746.5 kB Preview Download

Additional details

August 19, 2023
October 25, 2023