水-环己烷-二乙二醇丁醚三元体系的三液相相平衡

Three-liquid-phase Equilibria of Ternary System Water-Cyclohexane-Diethylene Glycol Monobutyl Ether

用改进的相体积法测定了水-环己烷-二乙二醇丁醚三元体系的相平衡,给出了不同温度下平衡共存三液相的体积分数及平衡共存三液相的相密度的共存曲线.实验结果表明,在平衡共存三液相中,水、环己烷和二乙二醇丁醚的体积分数随温度改变的变化曲线分别是倒'S'型,正'S'型,'结'型;将共存三液相的体积分数转化为对应的相密度后,相密度随温度改变的变化曲线也是规整的倒'S'型;而且,3条'S'曲线形状均表现出不对称的特性.因此,密度也可以用作描述体系的相平衡,而且在描述体系临界标度率时,密度可能是一个很好的序参量.

The equilibria of the three-liquid-phase for ternary system water-cyclohexane-diethylene glycol monobutyl ether were determined by the improved volume method, at the same time, the coexisting curves of the temperatures versus the volume fractions and the mass densities of the coexisting three liquids phases are reported. It is found that the coexisting curves of the temperatures versus the volume fractions of water, cyclohexane and diethylene glycol monobutyl ether are respectively inverse ＂S＂ type curve, positive ＂S＂ type curve and ＂knot-shape＂ curve. Simultaneously, when the volume fractions of coexisting three-liquid-phases are convened into mass densities, it is also found that the coexisting curve of temperatures versus mass densities of phases is also standard inverse ＂S＂ type curve. Furthermore, the three ＂S＂ type curves are all asymmetric, and the mass density may be used to describe the phase-equilibrium, moreover, the mass density may really be a good order parameter to describe the critical scaling behaviour.