HELMHOLTZ FREE ENERGY IN A SYSTEM OF ANISOTROPIC CHAINLIKE MOLECULES AND ITS APPLICATIONS FOR NORMAL MONOHYDRIC ALCOHOLS AND NORMAL ALKANES

摘要

A method for deriving the Helmholtz free energy in a system of chainlike molecules is presented, with which any perturbation theory of small molecules can be easily extended to chainlike molecules. Based on this, the authors obtained a theoretical model of anisotropic chainlike molecules in which various intermolecular energies were con- sidered. This model involves only segment parameters for chainlike molecules, and 3c and other molecular parameters are discarded. As can be seen from the calculations, the set of parameters in Table 1 represents the thermodynamic properties of 31 kinds of molecules simultaneously, e.g. phase equilibrium (Eq. 31), heat of vaporization (Eq. 32) and p-V-T behavior (Eq. 34). The calculations reveal that the theoretical model in this work reflects the microscopic characteristics of the systems and can be used for the prediction of certain properties to some extent.