RUI: Characterization of Reactive Transients in Heterogeneous Atmospheric Photochemistry

Colgate University, Hamilton NY

Investigators

Abstract

With this award, the Environmental Chemical Sciences Program of the Division of Chemistry is funding Professor Ephraim Woods of Colgate University to study short-lived chemical species that are generated by the interaction of light with aerosol particles which are similar to those found in the troposphere. One goal of the work is to determine the conditions that promote the growth of organic aerosol particles through photochemistry. These secondary organic aerosol particles influence climate through their effects on the Earth's radiation balance. In terms of broader scientific impact, this research is expected to lead to a better understanding of the processes that affect climate and help scientists to forge improved predictive models. Another impact is the professional development of the undergraduates at Colgate University who conduct this work. In participating as team members on this project, undergraduates gain experience in research methods and become better prepared for graduate work in the sciences. Experiments in this project are designed to examine photochemically generated transient species in aerosol systems using photoionization methods. One type of experiment will probe the formation of secondary organic aerosols (SOA) through the reactive uptake of volatile organic molecules (VOCs) with particle phase triplet photosensitizers. The goal of this work is to further understand how the structure and morphology of the air-particle interface influences the kinetics of this newly identified SOA formation mechanism. Another type of experiment investigates the production of radicals from nitrate-containing particles. A third experiment characterizes solvated electrons in environments that are unexplored and not accessible through other experiments. The investigation of aerosol properties and surfaces in these studies is expected to establish an improved molecular-level understanding of these complex chemical systems.