Original scientific paper

Light Scattering in Binary Liquid Mixtures. I. Isotropic Scattering

N. Šegudović ; Department of Physical Chemistry, Institute »Ruder Boskovic«
Gj. Deželić ; Andrija Stampar School of Public Health, Medical Faculty, University of Zagreb, 41000 Zagreb, Croatia, Yugoslavia

Abstract

The isotropic light scattering in liquid mixtures of small nonelectrolyte
molecules was studied from both the theoretical and the
experimental point of view. The necessity of the cross-term in the
isotropic Rayleigh ratio resulting from the correlation of fluctuations
in density and concentration is discussed. A new expression for this
term is derived and compared with the previously derived expression.
Isotropic scattering of various pure liquids and liquid mixtures
is determined at the wavelengths 546 and 436 nm and the reliability
of experimental data is discussed in great detail. Mixtures of cyclohexane, n-heptane and carbon tetrachloride (component 1) with
benzene and carbon disulfide (component 2) were examined. The
possibility of the determination of molecular weights from light
scattering experiments on such systems is discussed. The reliability
of the excess free energy of mixing data obtained by light scattering
is carefully considered. It is concluded that light scattering
phenomena can be explained by thermodynamics, but the light
scattering method is generally inferior to vapour pressure methods
both in sensitivity and accuracy, and because of the complexity
of the evaluation of data.

Keywords

Hrčak ID:

197035

URI

https://hrcak.srce.hr/197035

Publication date:

30.6.1973.

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