Surface tension for pure fluids by molecular thermodynamic model and PHTC equation of state

摘要

In this study, the modified square well model is combined with perturbed-hard-trimer-chain (PHTC) EOS to correlate the surface tension of normal alkanes and refrigerant fluids. The performance of the proposed model has been evaluated by calculating the surface tension of 15 hydrocarbons range within 112-440 K and pressures up to 4.72 x 10(-6) MPa. From 251 data points examined the average relative deviation (ARD) of the correlated and calculated densities and surface tension from the experimental ones was found to be 1.63% and 2.46%. Besides, some surface thermodynamic functions such as the surface entropy (S-S) and surface enthalpy (H-S) of studied liquids were also computed via our method. The ARD (in %) were found to be equal to 3.94 and 2.44, respectively. Finally, our method has also been employed to estimate the critical temperature of 15 hydrocarbons with ARD (in %) equal to 7.92.