This Career Advancement Award project is in the area of surface chemistry and in the subfield of interfacial vibrational spectroscopy. During the tenure of this twelve-month standard grant, Professor Guest and her students at the University of Cincinnati will construct a photoelastic modulator-based ellipsometer suitable for fast, in situ monitoring of the air-water interface. This apparatus will be used to demonstrate ellipsometric detection of adsorbed gases at the air-aqueous interface which represents an advance in the application of ellipsometry. This method has potential for development into an non-invasive, time-resolved monitor of gas coverage, depletion, and chemical reaction on liquid surfaces. In combination with other interfacially sensitive probes, this technique is expected to offer unambiguous new insights into the kinetics, dynamics, and spectroscopy of gaseous adsorbates at the air-aqueous interface. This Career Advancement Award project reflects Professor Guest's overall effort to revector her research direction toward the area of gas-liquid interfacial phenomena. A particular focus of this present work is the development of an ellipsometric approach to the study of heterogeneous atmospheric chemistry.
