CAREER: Understanding Molecular-level Processes of Gas-phase Ammonia Uptake by Aqueous Sulfuric Acid Surfaces using Broadband Sum Frequency Generation Spectroscopy

Ohio State University Research Foundation -Do Not Use, Columbus OH

Investigators

Abstract

Professor Heather Allen of Ohio State University has received a CAREER award from the Analytical and Surface Chemistry Program for sum frequency generation studies on gas-liquid surfaces, especially ones of environmental interest. Ammonia uptake by aqueous sulfuric acid solution surfaces will be investigated using broad-band SFG, allowing the acquisition of vibrational spectra specific to the surface region. The spectra will be interpreted to give molecular level pictures of the surface uptake mechanisms of the reactive gas by the liquid. The ammonia-sulfuric acid system has relevance to the formation and growth of ammonium sulfate aerosols throughout the troposphere and is particularly important in polluted urban atmospheres. The PI will incorporate problem-based-learning in undergraduate courses, and will sponsor a program that will award summer research internships with the goal of increasing the participation of women and underrepresented minorities in scientific research. Work on the chemical and physical properties of aerosols will lead to a better understanding of their role in atmospheric chemical cycles and in climate. Previous droplet-train experiments showed evidence for surface-mediated reactions, and new laser-based spectroscopies allow the examination of those reactions in a direct manner. Students involved in this research and education plan will be exposed to work that will lead to a better understanding of pollution, as well as the role of basic research in solving complex chemical problems relevant to society.