CAPS: Research

Gas Phase Oxidation

The great bulk of chemistry in the atmosphere occurs in the gas phase. Reduced material is emitted from the earth's surface, either by biological activity in general or human activity in particular. This material (much of it hydrocarbon based) is oxidized by photochemically induced radical mechanisms either completely into carbon dioxide or partially into carbonyls, soluble organic acids, and peroxides. Understanding how these oxidation mechanisms behave in detail is a major focus of both Prof. Donahue and Prof. Pandis. Of particular interest is understanding how different atmospheric conditions can lead to very different products from these mechanisms, and in particular how production of ozone and aerosol precursors may vary. A major portion of that work involves reproducing atmospheric oxidation sequences in controled laboratory experiments in order to isolate portions of the mechanisms and determine both branching patterns and specific reaction rate constants.