Thermodynamics Research Center / ThermoML | Thermochimica Acta

ABSTRACT

The phase diagram of biphenyl 3-hydroxybenzaldehyde and 4-bromochlorobenzene m-aminophenol systems show the formation of a eutectic with 0.935 mole fraction of biphenyl in the former case, and a monotectic and a eutectic with 0.150 and 0.996 respectively mole fractions of 4-bromochlorobenzene in the latter case. Growth kinetics of pure components, the eutectics and the monotectic have studied by measuring the rate of movement of solid-liquid interface which suggests the applicability of Hillig- Turnbull s equation. The thermodynamic functions such as heat of mixing, entropy of fusion, roughness parameter, interfacial energy and excess thermodynamic functions were calculated from the enthalpy of fusion values, determined by the DSC method. The interfacial energy of monotectic system satisfies the Cahn s wetting condition. The optical microphotograph of monotectic shows lamellar structure whereas eutectics show broken lamellar and lamellar pearlite structures.