Interfacial tension in immiscible mixtures of alkali halides

Abstract

The interfacial tension of the liquid-phase interface in seven immiscible reciprocal ternary mixtures of lithium fluoride with the following alkali halides: CsCl, KBr, RbBr, CsBr, KI, RbI, and CsI was measured using the cylinder weighing method over a wide temperature range. It was shown that for all mixtures the interfacial tension gradually decreases with growing temperature. The interfacial tension of the reciprocal ternary mixtures at a given temperature increases both with the alkali cation radius (K⁺ < Rb⁺ < Cs⁺) and with the radius of the halogen anion (Cl⁻ < Br⁻ < I⁻).