CCN activation of fumed silica aerosols mixed with soluble pollutants

Show full item record



Permalink

http://hdl.handle.net/10138/161556

Citation

Dalirian , M , Keskinen , H , Ahlm , L , Ylisirnio , A , Romakkaniemi , S , Laaksonen , A , Virtanen , A & Riipinen , I 2015 , ' CCN activation of fumed silica aerosols mixed with soluble pollutants ' , Atmospheric Chemistry and Physics , vol. 15 , no. 7 , pp. 3815-3829 . https://doi.org/10.5194/acp-15-3815-2015

Title: CCN activation of fumed silica aerosols mixed with soluble pollutants
Author: Dalirian, M.; Keskinen, H.; Ahlm, L.; Ylisirnio, A.; Romakkaniemi, S.; Laaksonen, A.; Virtanen, A.; Riipinen, I.
Contributor: University of Helsinki, Department of Physics
Date: 2015
Language: eng
Number of pages: 15
Belongs to series: Atmospheric Chemistry and Physics
ISSN: 1680-7316
URI: http://hdl.handle.net/10138/161556
Abstract: Particle-water interactions of completely soluble or insoluble particles are fairly well understood but less is known of aerosols consisting of mixtures of soluble and insoluble components. In this study, laboratory measurements were performed to investigate cloud condensation nuclei (CCN) activity of silica particles mixed with ammonium sulfate (a salt), sucrose (a sugar) and bovine serum albumin known as BSA (a protein). The agglomerated structure of the silica particles was investigated using measurements with a differential mobility analyser (DMA) and an aerosol particle mass analyser (APM). Based on these data, the particles were assumed to be compact agglomerates when studying their CCN activation capabilities. Furthermore, the critical super-saturations of particles consisting of pure and mixed soluble and insoluble compounds were explored using existing theoretical frameworks. These results showed that the CCN activation of single-component particles was in good agreement with Kohler- and adsorption theory based models when the agglomerated structure was accounted for. For mixed particles the CCN activation was governed by the soluble components, and the soluble fraction varied considerably with particle size for our wet-generated aerosols. Our results confirm the hypothesis that knowing the soluble fraction is the key parameter needed for describing the CCN activation of mixed aerosols, and highlight the importance of controlled coating techniques for acquiring a detailed understanding of the CCN activation of atmospheric insoluble particles mixed with soluble pollutants.
Subject: CONDENSATION NUCLEI ACTIVITY
PARTICULATE AIR-POLLUTION
FRACTAL-LIKE DIMENSION
REGIONAL DUST SAMPLES
DROPLET ACTIVATION
HYGROSCOPIC GROWTH
PARTICLE DENSITY
ATMOSPHERIC MEASUREMENTS
DIFFERENTIAL MOBILITY
INSOLUBLE PARTICLES
114 Physical sciences
Rights:


Files in this item

Total number of downloads: Loading...

Files Size Format View
acp_15_3815_2015.pdf 7.422Mb PDF View/Open

This item appears in the following Collection(s)

Show full item record