Indiana University Bloomington
Environmental Chemistry Lab



The Raff group studies thermal and photochemical reactions that occur on environmental surfaces (e.g., airborne particles, buildings, vegetation, etc.). The goal is to understand the chemical mechanisms responsible for the degradation of surface-adsorbed chemicals (of anthropogenic and biogenic origins) and the formation of the chemical oxidants that lead to their transformation. We are particularly interested in obtaining molecular-level insights into these processes and to understand their effects on air pollution and climate. In addition, we are interested in testing our theories and validating chemical mechanisms in the field and through modeling.

Research projects in the Raff group rely on an interdisciplinary and collaborative approach that provides group members with a strong background in:

  • analytical chemistry (e.g., spectroscopy, chromatography, and mass spectrometry),
  • synthetic chemistry (e.g., the preparation of analytical standards and gaseous reactants),
  • heterogeneous chemistry (mechanistic studies of reactions occurring at the air-solid and air-liquid interface).

Some specific topics we are interested in are:

  • Thermal and photochemical reactions of NOy (= NO, NO2, N2O5, HONO, HNO3, etc) and other oxidants with organic compounds on environmental surfaces.
  • Elucidating photochemical mechanisms that form highly reactive oxidants and their precursors on airborne particles.
  • Through or work we hope to obtain a basic understanding of the molecular processes that are essential for answering key environmental questions and developing effective solutions to problems related to pollution, human health, and climate.