用微扰理论研究链状流体的状态方程

Equation of State for Chain Molecules by Use of Perturbation Theory

本文用微扰理论建立了链状流体的分子热力学模型，并给出了体系Ｈｅｌｍｈｏｌｔｚ自由能函数及状态方程的表达式。对非极性流体，体系的热力学性质由硬球作用、成链作用及色散作用三部分组成。对极性链状流体，分子间作用还包括偶极作用及诱导作用。将此模型应用于正烷烃及正一元醇的计算，同时关联纯液体的密度和饱和蒸汽压，结果与实验值符合良好。本文中所用的参数具有明确的物理意义。与前人的工作相比较。

A new thermodynamic model for chain molecules is developed based on perturbation theory. The expressions for Helmholtz free energy and equation of state are given in explict form. For nonpolar chain fluids,the thermodynamic properties of system are the sum of three terms representing contributions from hard sphere,chain-forming and dispersion. For polar fluids,the dipolar and induction terms are accounted for association interaction. This model is applied to pure fluids of normal alkanes and normal alcohols. The liquid density and saturated vapor pressure are regressed simultaneously with satisfactory results. The parameters used here have a well defined physical significance. Compared with the previous results,this model is theoretically simple with good accuracy.