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| Titel |
Scanning supersaturation condensation particle counter applied as a nano-CCN counter for size-resolved analysis of the hygroscopicity and chemical composition of nanoparticles |
| VerfasserIn |
Z. Wang, H. Su, X. Wang, N. Ma, A. Wiedensohler, U. Pöschl, Y. Cheng |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 8, no. 5 ; Nr. 8, no. 5 (2015-05-21), S.2161-2172 |
| Datensatznummer |
250116366
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| Publikation (Nr.) |
 copernicus.org/amt-8-2161-2015.pdf |
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| Zusammenfassung |
| Knowledge about the chemical composition of aerosol particles is essential to
understand their formation and evolution in the atmosphere. Due to
analytical limitations, however, relatively little information is available
for sub-10 nm particles. We present the design of a nano-cloud condensation
nuclei counter (nano-CCNC) for measuring size-resolved hygroscopicity and
inferring chemical composition of sub-10 nm aerosol particles. We extend the
use of counting efficiency spectra from a water-based condensation particle
counter (CPC) and link it to the analysis of CCN activation spectra, which
provides a theoretical basis for the application of a scanning
supersaturation CPC (SS-CPC) as a nano-CCNC. Measurement procedures and data
analysis methods are demonstrated through laboratory experiments with
monodisperse particles of diameter down to 2.5 nm, where sodium chloride,
ammonium sulfate, sucrose and tungsten oxide can be easily discriminated by
different characteristic supersaturations of water droplet formation. A
near-linear relationship between hygroscopicity parameter κ and
organic mass fraction is also found for sucrose-ammonium sulfate mixtures.
The design is not limited to the water CPC, but also applies to CPCs with
other working fluids (e.g. butanol, perfluorotributylamine). We suggest that
a combination of SS-CPCs with multiple working fluids may provide further
insight into the chemical composition of nanoparticles and the role of
organic and inorganic compounds in the initial steps of atmospheric new
particle formation and growth. |
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