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Published on: April 3, 2018
Ultraviolet light-induced water-droplet formation from wet ambient air
Keitaro Yoshihara1, Yoshiki Takatori2, Koji Miyazaki3
1Toyota Physical and Chemical Research Institute, Aichi, Japan .
Abstract:
We report the formation of water droplets by irradiating wet ambient air with deep UV light. The light sources were either a continuous low-pressure mercury lamp or pulsed ArF laser, which both emit light shorter than 200 nm. Water droplets were produced in reaction vessels under different temperature, relative humidity, and moisture-supply conditions. The particles grew as large as about 0.2 mm. The suggested mechanism is discussed with the photo-dissociations of oxygen and successively formed ozone, and further dark reactions giving hydrogen peroxide as a seeding nucleus. Observed concentrations of intermediates were well explained by simulating the proposed chemical reactions. A possible application to artificial rain is briefly described.
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