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James Davies - University of California, Riverside

Host:  Miriam Freedman (867-4267)

"Probing the Physicochemical Properties of Organic-Inorganic Aerosol using Single Particle Levitation"

Abstract:

The physicochemical properties of aerosol particles play a pivotal role in dictating their interactions in the atmosphere, influencing important atmospheric processes such as cloud formation and light scattering. These attributes also significantly impact the role of aerosol on air quality at both regional and global scales. This presentation will introduce single particle levitation as an innovative tool for manipulating individual aerosol particles and measuring properties such as hygroscopicity, viscosity, diffusivity, phase state, and reactivity. Particles of a well-defined size and composition are exposed to controlled environmental conditions and their properties are characterized using light scattering. Emphasis will be placed on recent investigations of the properties of particles containing organic molecules and inorganic salts and those containing light-absorbing brown carbon chromophores. The ability to quantify essential morphological and rheological properties of levitated particles is highlighted, with implications extending to both atmospheric effects and their potential role in disease transmission. Furthermore, this presentation will discuss applications of mass spectrometry to single particle analysis and describe recent work comparing reaction rates in solid and liquid particles of the same chemical composition. This holistic characterization is essential for unraveling the nuanced roles of aerosol particles in both atmospheric and indoor environments, ultimately contributing to a more nuanced comprehension of their impact on our surroundings.