Accuracy of an analytic equation of state for hard-sphere multi-Yukawa chain fluids based on the first-order mean spherical approximation

The accuracy of analytical expressions of the compressibility factor and internal energy of chain fluids composed of m freely-jointed tangent hard-sphere monomers interacting through a hard-core n-Yukawa (HCnY) potential is further assessed. These expressions were obtained by combining the first-order mean spherical approximation (FMSA) for the monomer thermodynamic properties, the simplified exponential approximation (SEXP) for the monomer radial distribution function (RDF) at contact with the hard core, and the statistical associating fluid theory (SAFT) [Fluid Phase Equilibr. 218 (2004) 47]. The resulting expressions, which are simple to use for any m and n, are in overall good agreement with recent extensive Monte Carlo (MC) simulations performed on new HC2Y chain fluids with m = 2, 4, 8, 16. The absolute average deviations (AAD%) for the reduced pressure and internal energy are respectively within 6.0% and 3.8% of the simulation data.