Ostapchuk Y. Equilibration kinetics and properties of the methanol-hexane solution under gravity close to the critical temperature.

Equilibration kinetics and equilibrium properties of the inhomogeneous methanol-hexane solution under gravity in a wide temperature and concentration range including a neighbourhood of the critical consolute temperature have been investigated in the work. The nonmonotonic height dependence of effective relaxation times of the refractive index gradient has been obtained. It has been shown, that the equilibration process of an inhomogeneous system under gravity can be described by the scaling equation of nonequilibrium gravity effect. The temperature dependences of equilibrium optical and thermodynamic characteristics of the inhomogeneous solution under gravity close to the critical consolute temperature have been studied. The nonmonotonic temperature dependences of the refractive index and the solution density along the liquid-liquid coexistence curve have been revealed. The obtained result shows that these parameters can not be used as order parameters for the studied solution near the critical consolute temperature. The coexistence curve of the solution has been studied by using different parameters. It has been shown, that the molar concentration should be taken as the critical order parameter for the methanol-hexane solution.