Raman Spectroscopy of Water鈥揈thanol Solutions: The Estimation of Hydrogen Bonding Energy and the Appearance of Clathrate-like Structures in Solutions
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- 作者：Tatiana A. Dolenko ; Sergey A. Burikov ; Sergey A. Dolenko ; Alexander O. Efitorov ; Ivan V. Plastinin ; Viktor I. Yuzhakov ; Svetlana V. Patsaeva
- 刊名：Journal of Physical Chemistry A
- 出版年：2015
- 出版时间：November 5, 2015
- 年：2015
- 卷：119
- 期：44
- 页码：10806-10815
- 全文大小：497K
- ISSN：1520-5215
文摘
The structure of aqueous alcohol solutions at the molecular level for many decades has remained an intriguing topic in numerous theoretical and practical investigations. The aberrant thermodynamic properties of water鈥揳lcohol mixtures are believed to be caused by the differences in energy of hydrogen bonding between water鈥搘ater, alcohol鈥揳lcohol, and alcohol鈥搘ater molecules. We present the Raman scattering spectra of water, ethanol, and water鈥揺thanol solutions with 20 and 70 vol % of ethanol thoroughly measured and analyzed at temperatures varying from 鈭?0 to +70 掳C. Application of the MCR-ALS method allowed for each spectrum to extract contributions of molecules with different strengths of hydrogen bonding. The energy (enthalpy) of formation/weakening of hydrogen bonds was calculated using the slope of Van鈥檛 Hoff plot. The energy of hydrogen bonding in 20 vol % of ethanol was found the highest among all the samples. This finding further supports appearance of clathrate-like structures in water鈥揺thanol solutions with concentrations around 20 vol % of ethanol.