Liquid-liquid phase separation and critical exponents in ionic fluid mixtures

Abstract

The critical exponents of model ionic fluid mixtures exhibiting liquid-liquid phase separation are calculated analytically through the mean-spherical approximation. Classical exponents β and γ are found in agreement with the available experimental data for ionic fluids. The phase diagram of molten tetra-n-butylammonium picrate–1-chloroheptane is also well reproduced through the same theoretical approach, showing excellent agreement of the calculated exponent β with the experimental value. Possible applications to other multicomponent fluids are briefly discussed.