Thermodynamic properties of the two higher fullerites C₇₀ and C₉₆ along the liquid-vapor coexistence curve

A brief review is presented for the pre-history and discovery of fullerenes. Single-site potentials with parameters proposed by Girifalco was used to describe the interactions of the fullerene molecules C₇₀ and C₉₆. We present theoretical model for calculating the thermodynamic properties of liquid for both C₇₀ and C₉₆ by means of an improved equation of state (EOS), in which the particles are interacting via pair wise interaction composed of suitable linear combination of three Yukawa functions (3YK). The proposed equation of state provides a powerful mathematical formalism for the Helmholtz free energy and the pressure within the series mean-spherical approximation (SMSA) which are the basic ingredients to compute the liquid-vapour coexistence curve of C₇₀ and C₉₆ as well as the other thermodynamic properties for the bulk liquid and the vapour phases. The comparisons with Gibbs ensemble Monte Carlo (GEMC) simulations and the self-consistent Ornstein-Zernike approximation (SCOZA) were carried out. The estimated critical parameters for both C₇₀ and C₉₆ are T_C=2176K, ρ_C=0.44nm^-3, P_C=51.64 bars and T_C=2477K, ρC=0.32nm^-3, P_C=44.28 bars respectively. It is to be noted that the obtained results of the thermodynamic properties along the binodal curves of C₇₀ and C ₉₆ are exhibit interesting features.