Order parameter in the vicinity of the double critical point of stratification.

Abstract

The results have been presented of an investigation of the conductivity and IR absorption spectra of the propanol-water solution with a NaCl impurity having a double critical point of stratification. By making use of the conductivity measurement results, the phase diagrams have been restored with respect to each component of the solution. It has been shown that, in describing phase equilibria in multicomponent systems, the difference of the concentration of any component, including an impurity, as well as the difference of the conductivity and near-IR absorption in coexisting phases, may be chosen as the order parameter.