Determination of the UV radiation dose of an aerosol using UV-sensitive dyes to optimize UV room air filters
Final Report Abstract
This project aims to develop a model system avoiding the use of virus-containing aerosol to determine the ultraviolet (UV) radiation doses of UV-sensitive dyes, which correlates with the log-reduction doses of viral aerosols. First, a stable aerosol system that both contains a UV-sensitive dye and carrier liquid was sought. We tested 20 types of UV-sensitive dyes and only two of them satisfied our selection criteria. The three selection criteria for UV-sensitive dyes include high solubility in the carrier liquid, high extinction coefficients among 240-280 nm, and dye solutions that have a goodness-offit (R-squared) value above 0.99 in a simple linear regression. To determine the color intensity in aerosol liquid, we built a low-pressure impactor to collect aerosol droplets with a high deposition efficiency (90%). Our first results demonstrated that dye degradation in an aerosol droplet could be achieved by UV irradiation with a wavelength of 172 nm. The dye degradation is more pronounced when prolonging the aerosol residence time in the UV irradiator chamber. Moreover, we propose to use UV light with wavelengths greater than 260 nm for later studies, since the carrier liquid DEHS (Dioctyl sebacate) has a strong absorbance at UV light with wavelengths below 260 nm. The feasibility of using UVC-LED (275 nm) irradiation to degrade the UV-sensitive dye solution was already verified in this work. In future research, a UV radiation chamber with adjustable UV dose should be designed to determine the lower limit of UV dose for an aerosol droplet containing UV-sensitive dyes. Moreover, instead of a broad aerosol distribution, narrower aerosol fractions can be generated to investigate possible droplet size effects.
Publications
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Determination of the UV radiation dose of an aerosol using UV-sensitive dyes to optimize UV room air filters, Research Conference Pandemics, 2021, Conference Poster
Q. Fu, F.E. Kruis
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Determining the UV radiation dose of an aerosol using UV-sensitive dyes, 11th International Aerosol Conference, 2022, Conference Poster
Q. Fu, F.E. Kruis
