Diffusion Measurements in Binary Liquid Mixtures by Raman Spectroscopy
Diffusion Measurements in Binary Liquid Mixtures by Raman Spectroscopy
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DOI：
10.1366/000370207780466316
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发表时间：
2007-04
影响因子：
3.5
通讯作者：
R. W. Berg;S. B. Hansen;A. Shapiro;E. Stenby
中科院分区：
文献类型：
--
作者：
R. W. Berg;S. B. Hansen;A. Shapiro;E. Stenby
It is shown that Raman spectroscopy allows determination of the molar fractions in mixtures subjected to molecular diffusion. Spectra of three binary systems, benzene/n-hexane, benzene/cyclohexane, and benzene/acetone, were obtained during vertical (exchange) diffusion at several different heights (z) as a function of time. A procedure to determine time-dependent concentration profiles and diffusion coefficients is described in detail for one system, and results are given for the two other cases. For the system benzene/cyclohexane, much lower diffusion coefficients than reported in the literature were found, even in a thermostatically controlled diffusion cell, recording spectra through circulating water. For the system benzene/acetone, the determined diffusion coefficients were in good agreement with the literature data. The limitations of the Raman method are discussed, and it is concluded that many more systems ought to be studied. It is pointed out that diffusion profiles can be obtained in ternary and higher systems, where proper measurements are almost nonexistent.
