链状方阱流体的状态方程研究

为研究链状分子物质（如烷烃等）及其混合物的热力学性质，应用Ｗｅｒｔｈｅｉｍ的热力学微扰理论，在链状硬球流体状态方程的基础上，发展得到了链状方阱流体的状态方程。它可以表示成三部分：硬球贡献、方阱吸引势能贡献和成键贡献。在计算成键对压缩因子的贡献时，考虑到了成键对组成链的原子之间径向分布函数的影响。用得到的状态方程计算不同链长的链状方阱流体的压缩因子，其结果与分子模拟数据符合较好。

Equation of state for square-well chain fluids

In order to study the thermodynamic properties of chain molecules and their mixtures, an equation of state for homonuclear square well chain molecules is formulated by applying thermodynamic perturbation theory of Wertheim, on the basis of the equation of state for hard sphere chain fluids. The derived equation can be expressed into three parts: the square well repulsive energy contribution, bonding contribution, and the square well attractive energy contribution. It yields a very accurate prediction of the compressibility factor of different chain molecules including square well monomers and square well dimers as well as flexible chains with up to 15 bonds in a molecule. A large number of molecular simulation results are used to test the proposed equation. Good agreement between the calculated and the computer simulation data can be obtained from the equation of state.