二分量胶体悬浮系统的短时间动力学

SHORT-TIME DYNAMICS OF TWO-COMPONENTCOLLOIDAL SUSPENSIONS

研究了二分量带电粒子悬浮系统的短时间平动和转动自扩散系数 .由于存在静电相互作用和流体力学作用 ,扩散系数与两种粒子的尺寸比 ,它们的体积分数 ,以及所带的有效电荷都有关 .计入了流体力学相互作用对扩散张量的二体贡献和首项三体贡献 .计算结果表明 ,流体力学作用对于带电粒子系统的影响要小于它对硬球粒子系统的影响 .扩散系数随两种粒子的尺寸比和它们的体积分数变化的关系可以用有效硬球模型来解释 ,而其定性结果与实验相符合 .

We calculate the short-time translational, and rotational self-diffusion coefficients for charge-stabilized binary colloidal suspensions where the density of one component is very dilute. The two-body and leading three-body contributions of hydrodynamic interaction (HI) to the diffusion tensor are taken into account. Due to both electrostatic interactions and HI, the self-diffusion coefficients depend on effective charge numbers, volumn fractions and sizes of two kinds of spheres, and the results can be explained by the effective hard sphere model. The influence of HI on charge-stabilized binary systems is less than that on hard-sphere binary systems.