基于化学缔合的链状YUKAWA流体的状态方程

EQUATION OF STATE FOR CHAIN-LIKE YUKAWA FLUIDS BASED ON CHEMICAL ASSOCIATION

从Yukawa流体出发 ,采用化学缔合的统计力学理论建立了链状Yukawa流体的分子热力学模型 ,其亥氏函数由作为参考流体的硬球Yukawa流体的贡献和链节成键的贡献两部分组成 .采用链长为 2的链状Yukawa流体压缩因子的MonteCarlo模拟结果关联得到成键贡献项中空穴相关函数 ,对势能函数参数λ =1 8和λ =3 0时链长为 4和 8的链状Yukawa流体的压缩因子的预测与MonteCarlo数据能很好地吻合 ,比Wang和Chiew的微扰理论结果更好 .

A molecular thermodynamic model for the chain-like Yukawa fluid was derived by using statistical mechanics of chemical association. The Helmholtz function contained two terms, a reference term arising from the hard-core Yukawa fluid, and a bonding term due to the bonding of hard-core Yukawa segments. The cavity correlation function was obtained from the Monte Carlo simulation data of compressibility factors of dimer Yukawa fluids. Using this cavity correlation function the equation of state of chain-like Yukawa fluid was expressed analytically. The predicted results of compressibility factors are in excellent agreement with computer simulation of 4-mer and 8-mer chain-like Yukawa fluid for λ=1.8 and λ=3.0. The results are better than those of Wang and Chiew. Meanwhile the equation of state is simpler than SAFT-VR.