AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Formation, Morphology and Hygroscopic Growth of Indoor Aerosols Formed by Oxidation of Household Products
Andrew Hritz, Dabrina Dutcher, TIMOTHY RAYMOND, Bucknell University
Abstract Number: 315 Working Group: Indoor Aerosols
Abstract In this work, we have characterized the heterogeneous formation of particles from typical household materials and solvents. Gas phase VOCs are known to react with oxidants such as ozone to form new particles. Other household objects such as the foam mats and pressed wood furniture are known to emit formaldehyde and related products for the duration of the product’s lifetime. Chemicals such as formaldehyde are known to be irritants but less is known about how they contribute to particulate phase pollutants in household environments. Scented candles and air fresheners may also contribute significantly to indoor air pollution.
A smog-chamber was used to characterize the contribution of different household objects to particle formation. Our smog chamber consists of a one cubic meter Teflon bag. The rate, number and size concentration and other features of the particle formation were monitored by a scanning mobility particle sizer (SMPS) and optical particle counter (OPC). Additionally, the particles were collected and subsequently viewed on the atomic force microscope (AFM) and scanning electron microscope (SEM), depending on the particles’ size. We also used a Humidity Tandem Differential Mobility Analyzer (HTDMA), in which produced particles were subject to elevated humidities and temperatures, such as those found in human airways, and changes in physical size of the particles were monitored. The tendency of organic particles to grow in humid conditions depends on the chemical composition of the particles and thus needs to be measured directly. The final physical size of the particles determines where in the human airway the particles are likely to be collected and has significant implications in determining the associated health effects.
Results of this work, including particle growth, size distributions, morphology, and hygroscopic properties will be presented along with comparisons of pure-component VOCs that were constituents of the household products.