Description
INTRODUCTIONCommercial Condensation Particle Counters (CPCs) are mainly used to measure the number concentration of airborne particles (McMurry, 2000). Most ultrafine continuous flow CPCs use n-butanol as working fluid and have typical lower particle detection limits in the range between 2.5 and 10 nm (Stolzenburg and
McMurry, 1991). Given the fact that n-butanol CPCs are operated at fixed temperatures, the performance towards the detection of even smaller particles may be optimized by choosing appropriate temperature settings.
Until now the temperature dependence of heterogeneous nucleation of n-butanol vapor on nano-particles in a size-range down to 2.5 nm was not investigated. A topic, however, that is worth examining since it gives information on the saturation ratio which is needed to activate particles in this size range. Results of earlier
experiments with water vapor nucleating on silver particles have shown a theoretically unpredicted maximum in the onset saturation ratio as a function of temperature (Kupc et al., 2013). Further studies on the nucleation of n-propanol on sodium chloride particles in the temperature range from 262K to 287K
indicate a reversed trend of the onset saturation ratio compared to the Kelvin equation (Schobesberger et al., 2010). Due to the close chemical similarity of n-propanol and n-butanol, and the common use of n-butanol as a working fluid in commercial CPCs, the temperature dependence of heterogeneous nucleation of nbutanol on Ag and NaCl particles is investigated in this study.
| Period | 28 Jun 2017 |
|---|---|
| Event title | 20th International Conference on Nucleation and Atmospheric Aerosols |
| Event type | Conference |
| Location | Helsinki, FinlandShow on map |