The molecular structure of the surface of water-ethanol mixtures
ARTIGO
Inglês
Acompanhado de errata
Agradecimentos: The authors would like to add the following Acknowledgements to their published article: We acknowledge MAX IV Laboratory for time on Beamline I411 under Proposal 20210297. Research conducted at MAX IV, a Swedish national user facility, is supported by the Swedish Research council...
Agradecimentos: The authors would like to add the following Acknowledgements to their published article: We acknowledge MAX IV Laboratory for time on Beamline I411 under Proposal 20210297. Research conducted at MAX IV, a Swedish national user facility, is supported by the Swedish Research council under contract 2018-07152, the Swedish Governmental Agency for Innovation Systems under contract 2018-04969, and Formas under contract 2019-02496.
Abstract: Mixtures of water and alcohol exhibit an excess surface concentration of alcohol as a result of the amphiphilic nature of the alcohol molecule, which has important consequences for the physico-chemical properties of water-alcohol mixtures. Here we use a combination of intensity vibrational...
Abstract: Mixtures of water and alcohol exhibit an excess surface concentration of alcohol as a result of the amphiphilic nature of the alcohol molecule, which has important consequences for the physico-chemical properties of water-alcohol mixtures. Here we use a combination of intensity vibrational sum-frequency generation (VSFG) spectroscopy, heterodyne-detected VSFG (HD-VSFG), and core-level photoelectron spectroscopy (PES) to investigate the molecular properties of water-ethanol mixtures at the air-liquid interface. We find that increasing the ethanol concentration up to a molar fraction (MF) of 0.1 leads to a steep increase of the surface density of the ethanol molecules, and an increased ordering of the ethanol molecules at the surface. When the ethanol concentration is further increased, the surface density of ethanol remains more or less constant, while the orientation of the ethanol molecules becomes increasingly disordered. The used techniques of PES and VSFG provide complementary information on the density and orientation of ethanol molecules at the surface of water, thus providing new information on the molecular-scale properties of the surface of water-alcohol mixtures over a wide range of compositions. This information is invaluable in understanding the chemical and physical properties of water-alcohol mixtures
Fechado
The molecular structure of the surface of water-ethanol mixtures
The molecular structure of the surface of water-ethanol mixtures
Fontes
Physical chemistry chemical physics Vol. 23, n. 19 (May, 2021), p. 11568-11578 |