Ternary phase diagram, solid-liquid

Figure 26 shows the ternary phase diagrams (solubility isotherms) for three types of solid solution. The solubilities of the pure enantiomers are equal to SA, and the solid-liquid equilibria are represented by the curves ArA. The point r represents the equilibrium for the pseudoracemate, R, whose solubility is equal to 2Sd. In Fig. 26a the pseudoracemate has the same solubility as the enantiomers, that is, 2Sd = SA, and the solubility curve AA is a straight line parallel to the base of the triangle. In Figs. 26b and c, the solid solutions including the pseudoracemate are, respectively, more and less soluble than the enantiomers. 

The ternary-phase diagrams presented here illustrate only a small sample of the variety of equilibrium behaviors observed in solid-liquid equilibria in three-component systems. This subject, along with kinetic considerations make up much of the subject matter of a variety of fields, including metallurgy and... 

A general III—V solid-liquid ternary phase diagram is depicted in Figure 1. The two III—V binary systems, A-C and B-C, show similar behavior. Each system forms an equimolar compound,... 

AC or BC, which melts at a higher temperature than either of the pure elements (except for the InSb-Sb case). The binary phase diagram consists of two simple eutectic systems on either side of the compound (e.g., the A-AC and the AC-C systems). The third binary phase diagram represents solid-liquid equilibrium between elements from the same group. In Figure 1 the A-B portion of the ternary phase diagram is depicted as being isomorphous... 

Important to calculation of the ternary phase diagram, however, is the ratio of the liquid phase component activity coefficients to the solid component one. As illustrated for the A1-Ga-Sb system, the temperature and composition variation of the liquid phase component activity coefficients is largely cancelled by that of the solid component activity coefficient. 

ZA2 Zafarani-Moattar, M.T. and Nilgoo, D., Phase diagrams for liquid-liquid and liquid-solid equilibrium of the ternary polyfethylene glycol) dimethyl ether 2000 + sodium carbonate + water system, J. Chem. Eng. Data, 54, 2918, 2009. 

Phase diagrams are often constructed to provide a visual picture of the existence and extent of the presence of solid and liquid phases in binary, ternary and other mixtures of substances. Phase diagrams are normally two-component (binary) representations but multicomponent phase diagrams can also be constructed. Interactions between active substances and excipients can often be evaluated using phase diagrams. 

---