局部组成型的互扩散系数模型

Mutual Diffusion Coefficient Model Based on Local Composition Concept

根据局部组成概念建立了混合物中互扩散系数与自扩散系数的关系，并以分子集团迁移的概念建立了混合物中组分的自扩散系数的预测方法，由此预测二元系的自扩散系数和互扩散系数与实验结果符合良好，比经典的Ｈａｒｔｌｅｙ模型有了很大的改进。

Based on the local composition concept, a mutual diffusion coefficient model for binary sysems has been established. The mutual diffusion coefficient are calculated from the local volume fraction, activity coefficients and intradiffusion coefficients of mixture. The local volume fraction and activity coefficients of mixture can be predicted by Wilson model with parameters estimated from VLE data, while the intradiffusion coefficients of mixture can be calculated by the self diffusion coefficient of pure component, infinite diluted mutual diffusion coefficient and viscosity of mixtures based on the molecular cluster model developed in this work. The predicted intradiffusion coefficients and mutual diffusion coefficients for ordinary binary mixtures and that with a self associating component agree well with experimental data, the results are better than that by Hartley model for all systems and are similar with that by McKeigue model for mixtures with a self associating component.