Investigations of acetic acid and its quantitative effects on the quasi-liquid layer through 1H and 13C NMR analysis
Abstract
We report the study of a liquid-like phase that is found in aqueous CH 3COOH solutions frozen to temperatures as low as 233K. Previous studies have shown that heterogeneous reactions of gases with halides in the liquid layers of ice are the source of lower tropospheric ozone-destroying halogen radicals, often found in regions with sea ice. Thus the investigation of a quasi-liquid phase is important to the understanding and modeling of atmospheric composition and its influence on and dependence on the chemistry of ice and snow. The fractions and concentrations of water and CH3COOH in this quasi-liquid phase were measured by 1H and 13C NMR spectroscopy, and the experimental results compared to previous results in the literature. The temperature dependence of the acid concentration is described by the freezing point depression, where ideal solution behavior holds, leading to predictable values for real snow and ice samples.
Degree
M.S.
Advisors
Shepson, Purdue University.
Subject Area
Atmospheric Chemistry|Analytical chemistry
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