Thermoanalysis of binary condensed eutectic phases evincing molecular interactions

This article discusses the thermoanalytical model developed in the current work to study the influence of the molecular interactions between binary condensed eutectic phases in terms of excess thermodynamic functions that exhort the ability of providing quantitative idea of the interactions. Non-ideality of binary eutectic systems over the entire range of mole fraction composition is ascertained by subjecting the experimentally determined solidus-liquidus equilibrium data to thermodynamic analysis and thereby, apprehending quantitative idea about the nature of molecular interactions. The estimation of molecular interactions model of binary naphthalene-o-nitrophenol, alpha-naphthol-naphthalene, diphenylamine-alpha-naphthol, benzil-diphenyl, acenaphthene-antimonytrichloride and cadmium-bismuth eutectic systems authenticates the reliability of the excess functions, since the mixing of the eutectic phases either side of solidus-liquidus equilibrium curves of the systems is found to follow the criteria of spontaneity and Planck formulation S = klnw; where S, k and w, respectively, are the configurational entropy, Boltzmann constant and complexion number of constituent phase molecules. Moreover, the Guggenheim lattice theory applied to solidus mixtures at their liquidus temperatures offers supporting evidence to the essence of the excess functions and hence the thermomolecular interactions model.