根据分子间摩擦系数与组分自扩散系数关系,提出一个新的互扩散系数模型。模型分为3部分：组成项、自扩散系数和化学势与组分关系。采用文献自扩散系数值,并用不同状态方程以计算化学势与组分关系,模拟1 132～1 810℃之间不同组成二氧化碳气体混合物的互扩散系数,并与实验值做了比较。结果表明采用Peng-Robinson(PR),Redlich-Kwong(RK)及Van der Waals(VdW)方程计算化学势与组分关系而得到的模拟结果优于Virial方程,且平均误差在5%之内。
Simulations were carried out for studying the periodic phase separation of a symmetric binary polymer blend on the basis of Cahn-Hilliard-Cook theory. The time dependent interaction parameter x（τ） was assumed to undergo a step-wise oscillation. The hierarchic structures composed of both large and small domains were obtained. The mechanism of the periodic formation of hierarchic structures was also demonstrated.
A new model for self-diffusion coefficients was proposed based oil both the concepts of molecular free volume and activation energy. The unknown parameters of this model were clearly defined and compared with the Chapman-Enskog model. At the same time a new method for calculating activation energy was devised and applied to the new model. In addition, the free volume was defined by implementing the generic van der Waals equation of state, the radial distribution function of which was obtained by using the Morsali- Goharshadi empirical formula. Under the same conditions, the new model was better than the original free volume model.
