Towards an Understanding of the Influence of Sedimentation on Colloidal Aggregation by Peclet Number

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2005,（8）
• 页码范围: 2119-2122
• 页数: 4页
• 语种: 英文

摘要

The Peclet number is a useful index to estimate the importance of sedimentation as compared to the Brownian motion. However, how to choose the characteristic length scale for the Peclet number evaluation is rather criticalbecause the diffusion length increases as the square root of the time whereas the drifting length is linearly relatedto time. Our Brownian dynamics simulation shows that the degree of sedimentation influence on the coagulation decreases when the dispersion volume fraction increases. Therefore using a fixed length, such as the diameter of particle, as the characteristic length scale for Peclet number evaluation is not a good choice when dealing with the influence of sedimentation on coagulation. The simulations demonstrated that environmental factors in the coagulation process, such as dispersion volume fraction and size distribution, should be taken into account for more reasonable evaluation of the sedimentation influence.