Influence of Naturally Occurring Organic Surfactants on the Surface Tension of Sessile Droplets and Atmospheric Aerosols Measured with a Quasi-Elastic Laser Scattering System

摘要

Clouds are composed of atmospheric aerosols, micrometer sized aqueous droplets that are suspended in the air. These atmospheric aerosols play a key role in weather patterns and planet warming/cooling, making the understanding of their formation and propagation mechanisms highly important. Despite the critical role aerosols play, there is still a fundamental lack in understanding of the processes that drive their formation and growth because there is no direct way to measure the surface tension of aerosol droplets in the atmosphere. In Kohler theory, which governs the formation and growth of aerosols, aerosol formation activity is driven by size and surface tension of the droplet, making an accurate measurement of aerosol surface tension integral to fully understanding cloud formation and evolution properties. In this study we utilize a new laser-based technique to measure the surface tension of micrometer sized droplets through droplet-surface capillary resonance and their response to naturally occurring pinene and limonene molecules exposed to the droplet surface.