Coated soot particles with tunable, well-controlled properties generated in the laboratory with a miniCAST BC and a micro smog chamber
Loading...
Authors
Author (Corporation)
Publication date
28.05.2021
Typ of student thesis
Course of study
Collections
Type
01A - Journal article
Editors
Editor (Corporation)
Supervisor
Parent work
Journal of Aerosol Science
Special issue
DOI of the original publication
Link
Series
Series number
Volume
157
Issue / Number
Pages / Duration
Patent number
Publisher / Publishing institution
Elsevier
Place of publication / Event location
Edition
Version
Programming language
Assignee
Practice partner / Client
Abstract
A Micro Smog Chamber (MSC) was coupled for the first time with a miniCAST 5201 Type BC combustion generator with the aim to produce a series of stable and reproducible model aerosols simulating the physical properties of combustion particles present in ambient air. With this setup it was possible to generate particles ranging from “fresh” soot (single scattering albedo SSA≤0.05, absorption Ångström exponent AAE close to 1, high EC/TC mass fraction (approximately 90%) and mobility diameter typically <100 nm) to “aged” soot with different amounts of organic coating. The “aged” soot particles could grow up to 200 nm and exhibited high SSA (up to 0.7 at λ = 870 nm), an increased AAE (up to 1.7) and low EC/TC mass fraction (down to <10%). The ageing was achieved by coating the soot particles with increasing amounts of secondary organic matter (SOM) formed by the photo-oxidation of α-pinene or mesitylene in the MSC. Thereby, the SSA and AAE increased with coating thickness, while the EC/TC mass fraction decreased. Over the experimental period of 2 h, the generation of the “aged” soot aerosols was stable with a standard deviation in particle size and number concentration of <1% and <6%, respectively. The day-to-day reproducibility was also satisfactory: with α-pinene as SOM precursor the variability (standard deviation) in particle size was <2% and in the AAE and SSA < 6%. Particle number concentrations up to 106 cm−3 and mass concentrations up to 15 mg/m3 (depending on particle size and SOM amount) could be generated, much higher than what has been reported with other oxidation flow reactors. The generated carbonaceous aerosols could find useful applications in the field of aerosol instrument calibration, particularly in the standardization of filter-based absorption photometers under controlled conditions.
Keywords
Soot, Coating, Secondary organic matter, Micro smog chamber, Calibration aerosol
Subject (DDC)
Event
Exhibition start date
Exhibition end date
Conference start date
Conference end date
Date of the last check
ISBN
ISSN
0021-8502
1879-1964
1879-1964
Language
English
Created during FHNW affiliation
Yes
Strategic action fields FHNW
Publication status
Published
Review
Peer review of the complete publication
Open access category
Hybrid
Citation
Ess, M. N., Bertò, M., Keller, A., Gysel, M., & Vasilatou, K. (2021). Coated soot particles with tunable, well-controlled properties generated in the laboratory with a miniCAST BC and a micro smog chamber. Journal of Aerosol Science, 157. https://doi.org/10.1016/j.jaerosci.2021.105820