Abstract

A REVIEW ON TERNARY PHASE DIAGRAM: A PRACTICAL APPROACH FOR THE AREA AND CENTROID CALCULATION OF STABLE MICROEMULSION REGIONS

Muruganantham V., Jyothi Lakshmi V. Nair*, Venkateswarlu B. S., Margaret Chandira R. and Gopal Rao

ABSTRACT

Phase diagram is a graphical representation of phase changes in a material. It represents physical states of a substance under different conditions of temperature and pressure. A ternary diagram is a barycentric plot on 3 variables which sum to a constant. It graphically depicts the ratios of the three variables as positioned in an equilateral triangle. It is used in physical chemistry, petrology, mineralogy, metallurgy and other physical sciences to show the composition of system composed of three species. In population genetics, it is often called a Gibb’s triangle or a de- Finetti diagram. In game theory, it is often called a simplex plot. In a ternary plot, the proportions of the three variables a, b and c must sum to some constant “k”. Usually, this constant is represented as 1.0 or 100%. Because a+b+c = k for all substances being graphed, any one variable is not independent of the others; so only two variables must be known to find a samples point on the graph. The external variables that must be considered in ternary constitution are temperature, pressure, composition X, and composition Y. To construct a complete diagram representing all these variables would require the use of a four-dimensional space. It is customary to assume pressure constant (atmospheric pressure) and to construct a three-dimensional (3-D) diagram representing, as variables, the temperature and two concentration parameters. Therefore, in any application of the phase rule, it should be recalled that one degree of freedom has been exercised in the initial construction of the 3-D diagram by electing to draw it at one atmosphere of pressure.

Keywords: Phase diagram, ternary systems, isothermal, liquidus, fraction lines.