Coexistence curve near the binary mixture critical solution point: Noncritical fluctuations and Fisher renormalization

摘要

It is shown, within the framework of the fluctuation theory based on a microscopic Landaundash;Ginzburgndash;Wilson Hamiltonian for a twohyphen;component fluid, that under the constraint of fixed total liquid density the temperature versus composition phase diagram possesses a diameter that satisfies the rectilinear law in the asymptotic region near the critical solution point. The width of the coexistence region as well as the leading corrections to scaling have Fisherhyphen;renormalized exponents. These results also apply to mixtures with both upper and lower critical solution points.