Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
https://doi.org/10.5194/acp-2017-1066
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article
07 Dec 2017
Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Atmospheric Chemistry and Physics (ACP).
Predicting the glass transition temperature and viscosity of secondary organic material using molecular composition
Wing-Sy Wong DeRieux1,*, Ying Li1,*, Peng Lin2, Julia Laskin2, Alexander Laskin2, Allan K. Bertram3, Sergey A. Nizkorodov1, and Manabu Shiraiwa1 1Department of Chemistry, University of California, Irvine, CA 92697-2025, USA
2Department of Chemistry, Purdue University, West Lafayette, IN 47907-2084, USA
3Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
*These authors contributed equally to this work.
Abstract. Secondary organic aerosols (SOA) account for a large fraction of submicron particles in the atmosphere. SOA can occur in amorphous solid or semi-solid phase states depending on chemical composition, relative humidity (RH), and temperature. The phase transition between amorphous solid and semi-solid states occurs at the glass transition temperature (Tg). We have recently developed a method to estimate Tg of pure compounds containing carbon, hydrogen, and oxygen atoms (CHO compounds) with molar mass less than 450 g mol−1 based on their molar mass and atomic O : C ratio. In this study, we refine and extend this method for CH and CHO compounds with molar mass up to ~ 1100 g mol−1 using the number of carbon, hydrogen, and oxygen atoms. We predict viscosity from the Tg-scaled Arrhenius plot of fragility (viscosity vs. Tg / T) as a function of the fragility parameter D. We compiled D values of organic compounds from literature, and found that D approaches a lower limit of ~ 10 (±1.7) as the molar mass increases. We estimated viscosity of α-pinene and isoprene SOA as a function of RH by accounting for hygroscopic growth of SOA and applying the Gordon-Taylor mixing rule, reproducing previously published experimental measurements very well. Sensitivity studies were conducted to evaluate impacts of Tg, D, hygroscopicity parameter (κ), and the Gordon-Taylor constant on viscosity predictions. Viscosity of toluene SOA was predicted using the elemental composition obtained by high-resolution mass spectrometry (HRMS), resulting in a good agreement with the measured viscosity. We also estimated viscosity of biomass burning particles using the chemical composition measured by HRMS with two different ionization techniques: electrospray ionization (ESI) and atmospheric pressure photoionization (APPI). Due to differences in detected organic compounds and signal intensity, predicted viscosities at low RH based on ESI and APPI measurements differ by 2–5 orders of magnitude. Complementary measurements of viscosity and chemical composition are desired to further constrain RH-dependent viscosity in future studies.

Citation: DeRieux, W.-S. W., Li, Y., Lin, P., Laskin, J., Laskin, A., Bertram, A. K., Nizkorodov, S. A., and Shiraiwa, M.: Predicting the glass transition temperature and viscosity of secondary organic material using molecular composition, Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2017-1066, in review, 2017.
Wing-Sy Wong DeRieux et al.
Wing-Sy Wong DeRieux et al.
Wing-Sy Wong DeRieux et al.

Viewed

Total article views: 213 (including HTML, PDF, and XML)

HTML PDF XML Total Supplement BibTeX EndNote
146 65 2 213 8 1 3

Views and downloads (calculated since 07 Dec 2017)

Cumulative views and downloads (calculated since 07 Dec 2017)

Viewed (geographical distribution)

Total article views: 213 (including HTML, PDF, and XML)

Thereof 213 with geography defined and 0 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 11 Dec 2017
Publications Copernicus
Download
Short summary
The phase transition of organic particles between glassy and semi-solid states occurs at the glass transition temperature. We developed a method to predict glass transition temperatures and viscosity of secondary organic aerosols using molecular composition, providing consistent results will viscosity measurements. Viscosity of biomass burning particles was also estimated using the chemical composition measured by high resolution mass spectrometry with two different ionization techniques.
The phase transition of organic particles between glassy and semi-solid states occurs at the...
Share