Equation of state of chain molecules

Abstract

The formerly proposed equation of state of fused hard‐sphere molecules is applied to evaluate the compressibility factor of systems of flexible chains. A fair agreement with the available Monte Carlo data is obtained. Next, the equation of state extended to mixtures is used to predict the P–V–T behavior of binary systems composed of simple hard‐body chains differing in the number of atoms in molecules. Good accordance of the calculated and pseudoexperimental values—within the experimental errors of the data—is obtained. To get further experimental data for pure chain molecules and their mixtures Monte Carlo simulations were performed for the system of linear tetraatomic molecules with the site–site length l*=1 and their equimolar mixtures with hard dumbbells at several densities. Comparison of the results for the linear tetraatomics with data on the corresponding flexible chain molecule system reveals a good agreement of the data. The proposed equation of state describes adequately the behavior of both the pure fluid and mixtures.