物理化学学报Issue(3)：413-422,10.DOI:10.3866/PKU.WHXB201401203
扩散模型和凝聚模型耦合作用下胶体凝聚动力学的Monte Carlo模拟研究
Coupling Effects of Diffusive Model and Sticking Model on Aggregation Kinetics of Colloidal Particles:A Monte Carlo Simulation Study
摘要
Abstract
The effects of the diffusive (Ds(γ)=D0×sγ) and sticking (Pij(σ)=P0×(i×j)σ) models on the colloidal suspension evolution, cluster-size distribution and scaling, time dependence of weight-averaged cluster size, and the fractal dimensions of aggregates are investigated. Simulations of the aggregation kinetics are carried out for a wide range of diffusivity exponentγand sticking-probability exponentσvalues.γ<0 andσ>0 have similar effects on the col oidal aggregation kinetics. The mechanism of transition from slow to fast aggregation is quantitatively analyzed. The physical significance of a cluster-cluster aggregation model, leading to a diffusion-limited aggregation model, is proposed.γ>>0 corresponds to the directional movement of clusters or primary particles, rather than random Brownian motion. The driving force for this directional movement may be a strong long-range van der Waals force, electric force of the largest cluster, or external force from the boundary.σ<<0 decreases the aggregation velocity of colloidal particles, with the evolution of the colloidal suspension. This may correspond to the largest cluster being a repulsive center, and a repulsive force existing between clusters or primary particles. The simulation confirms particle aggregation involving the weight-averaged size growing exponential y at first, but obeying a power law later. The aggregation kinetics is a positive-feedback nonlinear process asσ>0, but a negative-feedback process asσ<0.关键词
扩散模型/凝聚模型/扩散指数/凝聚概率指数/凝聚动力学/Monte Carlo模拟Key words
Diffusive model/Sticking model/Diffusivity exponent/Sticking-probability exponent/Aggregation kinetics/Monte Carlo simulation分类
化学化工引用本文复制引用
熊海灵,杨志敏,李航..扩散模型和凝聚模型耦合作用下胶体凝聚动力学的Monte Carlo模拟研究[J].物理化学学报,2014,(3):413-422,10.基金项目
The project was supported by the National Natural Science Foundation of China (41271292)@@@@国家自然科学基金(41271292)资助项目 （41271292）
