Calculation of the T-X phase diagram and the thermodynamic quantities for the binary mixtures of Tetradecane plus Hexadecane using the Landau mean field model

Abstract

The Landau model is used to calculate the T - X phase diagram and the temperature dependence of the thermodynamic quantities near the phase transitions in the binary mixtures of tetradecane + hexadecane. The phase line equations are fitted to the experimental T - X phase diagram (liquidus + solid solution + solidus) and to the temperature dependence of the enthalpy for the solid (triclinic) solution + solid (rotator) solution from the literature for this binary mixture. By determining the fitted parameters, the thermodynamic quantities are calculated near the phase transitions in the tetradecane + hexadecane. Our T- X phase diagram explains the observed behaviour of the transitions for the binary mixtures studied. On the basis of the experimental enthalpy, calculated thermodynamic quantities exhibit the expected critical behaviour near the phase transitions from the Landau mean field model, which can be compared with the experimental data for tetradecane + hexadecane.