Guest–guest and guest–host interactions in ethanol, propan-1-ol, and propan-2-ol clathrate hydrate forming systems

Abstract

In the present study, Raman spectroscopic measurements were performed using clathrate hydrate samples composed of ethanol, propan-1-ol, or propan-2-ol + deuterated methane + deuterium oxide. The temperature of the samples was stepwise increased from 93 K to 263 K in steps of 10 K or 20 K to decompose the clathrate hydrate samples during the measurements. The Raman spectra of the alcohols + deuterated methane hydrate sample in the C–H symmetric vibration region were similar to that of pure vapor alcohols, which indicates the weak guest alcohol–host water interaction although alcohols are hydrophilic compounds. In the propan-2-ol + deuterated methane + deuterium oxide system, the formation of two compounds having different composition from structure II propan-2-ol + deuterated methane clathrate hydrate was observed.