We present a theoretical model for calculating the thermodynamic properties of liquid C60 by means of an improved equation of state (EOS), in which the particles interact via pairwise interaction composed of hard-core plus suitable linear combinations of three Yukawa functions. The proposed EOS provides simple analytical expressions for Helmholtz free energy and pressure, which are the basic ingredients to compute the liquid-vapour coexistence curve of C60 as well as all other thermodynamic properties for the bulk liquid and vapour phases. The comparisons with computer simulation results, based on Girifalco potential, suggest the importance of treating the attractive tail of the potential accurately. It is to be noted that the obtained results of the thermodynamic properties along the binodal curve of C60 exhibit interesting features; in particular, the vapour phase shows abnormal behaviour of its isothermal compressibility and configurational heat capacity. The estimated critical parameters Tc = 2008.8 K, ρc = 0.50 nm-3 and Pc = 54.8 bars are in good agreement with NVT-Monte Carlo simulation predictions. The critical parameters of C60 are compared with those of liquid metals, non-metals and some hydrocarbons.
|الصفحات (من إلى)||564-581|
|دورية||Physics and Chemistry of Liquids|
|المعرِّفات الرقمية للأشياء|
|حالة النشر||Published - أكتوبر 2009|
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