INTERFACE IN IMMISCIBLE IONIC MELTS

Abstract

The results of the study of the interface properties for immiscible mixtures LiF + KBr, LiF + CsCl, LiF + RbBr, LiF + KI, LiF + CsBr, LiF + RbI, LiF + CsI, LiCl + AgBr, LiCl + AgI и NaCl+AgI are summarized. It is established that the thickness of the interface increases when the temperature grows, tending to infinity near the critical mixing temperature. At equal temperature and the ratio of ion sizes, the layer thickness for melts containing silver halides turned out to be less than in mixtures of alkali metal halides. The surface energy for mixtures of alkali metal halides decreases as the temperature increases, obeying a power equation with a critical exponent equal to 1.5 in the vicinity of the critical mixing temperature. The critical exponent for the galvanic potential for mixtures containing silver halide turned out to be 18% less than the critical exponent for interfacial tension, which is due to the peculiarities of the chemical bond of silver halides. It is shown that at the same temperature, an increase in the size difference of the mixed ions leads to an increase in the energy and a decrease in the diffusivity of the transition layer due to a decrease in the mutual solubility of the components in this direction.