基于化学缔合统计理论的链状流体状态方程

基于化学缔合统计理论的链状流体状态方程(EOS)能够反映实际分子的形状、链节成链、缔合等具体信息,在实际流体热力学性质计算中有着广泛应用.一般的链状流体EOS仅考虑相邻链节间的相关性,我们则借助统计力学和计算机模拟结果在模型中纳入了相间链节间的相关性,获得的硬球链流体(HSCF)模型能够更好地预测模型流体的压缩因子和第二维里系数.以HSCF为参考,引入方阱色散微扰项获得了实际方阱链流体(SWCF)EOS;结合根据黏滞球模型导得的缔合项,进一步构建了缔合流体EOS.最近,我们根据微扰理论和积分方程方法又开发了一新的变阱宽方阱链流体(SWCF-VR)模型.SWCF和SWCF-VREOSs可很好地用于计算小分子、聚合物、离子液体等纯流体及混合物的相行为、热焓、表面张力、黏度等热力学及传递性质,显示了模型良好的工程应用价值.本文就本课题组多年来在自由空间范畴内基于化学缔合统计理论开发链状流体EOS及其实际应用作系统的总结.

Equation of state for chain-like fluid based on statistical theory for chemical association

The equations of state （EOSs） for chain-like fluid based on statistical theory for chemical association can characterize some detailed information of real molecular structure such as molecular shape,chain connection,associations and so on,and have been applied to represent the thermodynamic properties of real fluid extensively.Usually,only the contribution of the interactions between nearest-neighbor segments in chain-like EOS was included.Based on statistical mechanics and molecular simulation,the interactions between next-to-nearest-neighbor segments were also considered in our model,and,as a result,more accurate compressibility factor and the second viral coefficients of model fluid were produced.Coupling with a square-well （SW） dispersion term,an EOS for real square well chain fluid （SWCF） was obtained.The SWCF EOS was then extended to association fluid in virtue of an association contribution derived from stick sphere model.Recently,a new EOS for SWCF with variable range （SWCF-VR） was developed based on perturbation theory and integral equation in this lab.Both SWCF and SWCF-VR EOSs can well be applied to model phase behavior,caloric properties,surface tension,viscosity,etc.for normal small molecules,polymers,ionic liquids and so on suggesting that our models have a good application in practice.