Attenuated total reflection infrared spectroscopy of ice films

CHED 1368

Gustavo M. Riggio, griggio@rmc.edu and Rebecca R. H. Michelsen, rmichelsen@rmc.edu. Department of Chemistry, Randolph-Macon College, Ashland, VA 23005
Snow and ice play an important role in the composition of the atmosphere. Near its melting point, ice demonstrates a mobile, dynamic layer where adsorption of gases and chemical reactions are likely to occur. In order to investigate ice films, an attenuated total reflection infrared (ATR-IR) spectroscopy assembly with low-temperature capability and a customized gas-handling apparatus were designed and implemented. ATR-IR allows investigation of ice films without interference from water vapor. Accordingly, this technique can investigate ice at temperatures relevant to the lower atmosphere at high latitudes (240-273 K). Gas-phase molecular probes (acetic acid and pyridine) were used to observe the chemical environment of the ice. The feasibility of using this technique to measure the proton-donating ability of the dynamic ice surface will be assessed. Both the design of the experiment and preliminary spectra of ice will be presented.