Generating an aerosol of homogeneous, non-spherical particles and measuring their bipolar charge distribution
نویسندگان
چکیده
The Aerodynamic Aerosol Classifier (AAC) and Differential Mobility Analyzer (DMA) are aerosol classifiers commonly used to generate a monodispersed by selecting particles within narrow range of relaxation times or electrical mobilities, respectively. However, generating an homogeneous particles, which has ranges particle mass, mobility time simultaneously, with either these methods is challenging. Particles classified the DMA often not (or monodispersed) due multiply-charged particles. While AAC overcomes this challenge for spherical homogeneity achieved non-spherical their effective density varying size. This study demonstrates using in tandem homogeneous, approach validated scanning electron microscope (SEM) images measurements tandem-classified highlight homogeneity. To limit effects multiple charging during classification, only subset setpoints permitted. representative “average” from same source, low-density deviates most morphology, thus, provides insights into upper bound other properties, such as charging. Using select bipolar charge distribution soot aggregates then measured another DMA. AAC-DMA-DMA demonstrated measure up 17 individual states (i.e. ?8 +8) after neutralization (with 85Kr) size-resolved, diameters between 80 433 nm. obtain higher charges than predicted theory, overestimates uncharged fraction (by 0.042–0.069) and, lesser extent, single fractions 0.037) aggregates, while underestimating proportion 0.135 cumulatively at one size 0.039 state size). These discrepancies represent average source flame soot.
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ژورنال
عنوان ژورنال: Journal of Aerosol Science
سال: 2021
ISSN: ['0021-8502', '1879-1964']
DOI: https://doi.org/10.1016/j.jaerosci.2020.105705