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The effect of carrier gas contaminants on the charging probability of aerosols under bipolar charging conditions.

Steiner G, Reischl GP - J Aerosol Sci (2012)

Bottom Line: A recently developed high resolution mobility spectrometer allows the precise determination of the ions' electrical mobility; an empirical mass-mobility relationship was used to approximate the corresponding ion masses.Since the ion properties control the charging process of aerosols, it was further investigated how the different ion properties affect the calculation of the charging probabilities of aerosols.The results show that despite large variations of the ions' properties, only a minor effect on the calculated charging probabilities can be found.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Wien, Austria ; Department of Physics, University of Helsinki, P.O. Box 64, 00014, Finland.

ABSTRACT
This work concentrates on the experimental determination of the properties of ionic molecular clusters that are produced in the bipolar ionic atmosphere of a radioactivity based (241)Am charger. The main scope of this study was to investigate the dependency of the ions' properties on carrier gas contaminants caused by the evaporation of trace gases from different kinds of frequently encountered tubing materials. A recently developed high resolution mobility spectrometer allows the precise determination of the ions' electrical mobility; an empirical mass-mobility relationship was used to approximate the corresponding ion masses. It was found that impurities in the carrier gas dramatically change the pattern of the ion mobility/size distribution, resulting in very different ion properties that strongly depend on the carrier gas composition. Since the ion properties control the charging process of aerosols, it was further investigated how the different ion properties affect the calculation of the charging probabilities of aerosols. The results show that despite large variations of the ions' properties, only a minor effect on the calculated charging probabilities can be found.

No MeSH data available.


Related in: MedlinePlus

Most extreme data sets for the calculated charging probabilities only considering singly charged particles. Just minor differences in the charging probabilities are found despite the very different ion properties used for the calculation.
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f0040: Most extreme data sets for the calculated charging probabilities only considering singly charged particles. Just minor differences in the charging probabilities are found despite the very different ion properties used for the calculation.

Mentions: With the necessary input parameters available, the charging probabilities for aerosol particles that have been exposed to a bipolar ionic atmosphere can be computed according to Fuchs's theory. To unambiguously represent the calculated charging probabilities. Fig. 8 shows only the most extreme data sets for both ion polarities for singly charged particles. It has to be noted that according to Fuchs' theory, there already is a significant amount of doubly charged particles in the size range from 30 to 100 nm. However, to avoid an “overload” of information and to keep the picture as simple as possible, we focus on the calculated charging probabilities for only singly charged particles. For positive polarity, the ion properties determined while using the PVC fabric hose in front of the charger deliver the highest charging probability; the data corresponding to the polycarbonate tubing give the lowest charging probabilities. For negative polarity, the ion properties given by Reischl et al. (1996) yield the highest charging probability, the dataset involving the polyurethane tubing shows the lowest charging probabilities. All the other calculated charging probabilities, corresponding to the other ion properties determined while using the other tubing material, would lie in-between the displayed calculations.


The effect of carrier gas contaminants on the charging probability of aerosols under bipolar charging conditions.

Steiner G, Reischl GP - J Aerosol Sci (2012)

Most extreme data sets for the calculated charging probabilities only considering singly charged particles. Just minor differences in the charging probabilities are found despite the very different ion properties used for the calculation.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3473358&req=5

f0040: Most extreme data sets for the calculated charging probabilities only considering singly charged particles. Just minor differences in the charging probabilities are found despite the very different ion properties used for the calculation.
Mentions: With the necessary input parameters available, the charging probabilities for aerosol particles that have been exposed to a bipolar ionic atmosphere can be computed according to Fuchs's theory. To unambiguously represent the calculated charging probabilities. Fig. 8 shows only the most extreme data sets for both ion polarities for singly charged particles. It has to be noted that according to Fuchs' theory, there already is a significant amount of doubly charged particles in the size range from 30 to 100 nm. However, to avoid an “overload” of information and to keep the picture as simple as possible, we focus on the calculated charging probabilities for only singly charged particles. For positive polarity, the ion properties determined while using the PVC fabric hose in front of the charger deliver the highest charging probability; the data corresponding to the polycarbonate tubing give the lowest charging probabilities. For negative polarity, the ion properties given by Reischl et al. (1996) yield the highest charging probability, the dataset involving the polyurethane tubing shows the lowest charging probabilities. All the other calculated charging probabilities, corresponding to the other ion properties determined while using the other tubing material, would lie in-between the displayed calculations.

Bottom Line: A recently developed high resolution mobility spectrometer allows the precise determination of the ions' electrical mobility; an empirical mass-mobility relationship was used to approximate the corresponding ion masses.Since the ion properties control the charging process of aerosols, it was further investigated how the different ion properties affect the calculation of the charging probabilities of aerosols.The results show that despite large variations of the ions' properties, only a minor effect on the calculated charging probabilities can be found.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Wien, Austria ; Department of Physics, University of Helsinki, P.O. Box 64, 00014, Finland.

ABSTRACT
This work concentrates on the experimental determination of the properties of ionic molecular clusters that are produced in the bipolar ionic atmosphere of a radioactivity based (241)Am charger. The main scope of this study was to investigate the dependency of the ions' properties on carrier gas contaminants caused by the evaporation of trace gases from different kinds of frequently encountered tubing materials. A recently developed high resolution mobility spectrometer allows the precise determination of the ions' electrical mobility; an empirical mass-mobility relationship was used to approximate the corresponding ion masses. It was found that impurities in the carrier gas dramatically change the pattern of the ion mobility/size distribution, resulting in very different ion properties that strongly depend on the carrier gas composition. Since the ion properties control the charging process of aerosols, it was further investigated how the different ion properties affect the calculation of the charging probabilities of aerosols. The results show that despite large variations of the ions' properties, only a minor effect on the calculated charging probabilities can be found.

No MeSH data available.


Related in: MedlinePlus