Journal article
Physical properties of secondary photochemical aerosol from OH oxidation of a cyclic siloxane
Atmospheric chemistry and physics, Vol.19(3), pp.1649-1664
02/08/2019
DOI: 10.5194/acp-19-1649-2019
PMCID: PMC6936766
PMID: 31889955
Abstract
Cyclic volatile methyl siloxanes (cVMS) are high-production chemicals present in many personal care products. They are volatile, hydrophobic, and relatively long-lived due to slow oxidation kinetics. Evidence from chamber and ambient studies indicates that oxidation products may be found in the condensed aerosol phase. In this work, we use an oxidation flow reactor to produce ∼100 µg m−3 of organosilicon aerosol from OH oxidation of decamethylcyclopentasiloxane (D5) with aerosol mass fractions (i.e., yields) of 0.2–0.5. The aerosols were assessed for concentration, size distribution, morphology, sensitivity to seed aerosol, hygroscopicity, volatility and chemical composition through a combination of aerosol size distribution measurement, tandem differential mobility analysis, and electron microscopy. Similar aerosols were produced when vapor from solid antiperspirant was used as the reaction precursor. Aerosol yield was sensitive to chamber OH and to seed aerosol, suggesting sensitivity of lower-volatility species and recovered yields to oxidation conditions and chamber operation. The D5 oxidation aerosol products were relatively non-hygroscopic, with an average hygroscopicity kappa of ∼0.01, and nearly non-volatile up to 190 ∘C temperature. Parameters for exploratory treatment as a semi-volatile organic aerosol in atmospheric models are provided.
Details
- Title: Subtitle
- Physical properties of secondary photochemical aerosol from OH oxidation of a cyclic siloxane
- Creators
- Nathan J JanechekRachel F MarekNathan BryngelsonAshish SinghRobert L BullardWilliam H BruneCharles O Stanier
- Resource Type
- Journal article
- Publication Details
- Atmospheric chemistry and physics, Vol.19(3), pp.1649-1664
- DOI
- 10.5194/acp-19-1649-2019
- PMID
- 31889955
- PMCID
- PMC6936766
- NLM abbreviation
- Atmos Chem Phys
- ISSN
- 1680-7324
- eISSN
- 1680-7324
- Grant note
- DOI: 10.13039/100000001, name: National Science Foundation, award: ATM-0748602
- Language
- English
- Date published
- 02/08/2019
- Academic Unit
- Iowa Technology Institute; IIHR--Hydroscience and Engineering; Chemical and Biochemical Engineering; Iowa Superfund Research Program
- Record Identifier
- 9983997421102771
Metrics
26 Record Views