Department of Human and Engineered Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8563, Japan.
J Colloid Interface Sci. 2011 Oct 15;362(2):633-7. doi: 10.1016/j.jcis.2011.07.012. Epub 2011 Jul 21.
A Brownian dynamics simulation has been used to investigate the aggregation kinetics of bimodal colloidal mixtures with similar surface chemistries but different sizes, driven by the DLVO interaction potential. The time evolution of structural formation is examined by the mean number of neighbors under fast and slow aggregation regions. It was found that the electrolyte ionic strength affects the kinetic pattern of colloidal aggregation. Under the high electrolyte ionic strength conditions (fast aggregation), the selective aggregation of the least stable single component can take place in the early stage, while the other component is enriched in this least stable component in the later stage. With the ionic strength decreasing (towards the slow aggregation), the hybrid aggregation (selective aggregation and heteroaggregation) gradually dominates the aggregation kinetics. Also in the early stage, this evolves to the heteroaggregation of different components under lower ionic strength conditions. The volume fraction has no obvious influence on this kinetic pattern in the early stage.
采用布朗动力学模拟研究了具有相似表面化学但不同尺寸的双模态胶体混合物在 DLVO 相互作用势驱动下的聚集动力学。通过快速和缓慢聚集区域下的平均近邻数来考察结构形成的时间演化。结果发现，电解质离子强度会影响胶体聚集的动力学模式。在高电解质离子强度条件下（快速聚集），最不稳定的单一组分可能在早期发生选择性聚集，而在后期，另一组分则在这种最不稳定的组分中富集。随着离子强度的降低（向缓慢聚集），混合聚集（选择性聚集和异质聚集）逐渐主导聚集动力学。同样在早期阶段，在较低的离子强度条件下，这种情况演变为不同成分的异质聚集。在早期阶段，体积分数对这种动力学模式没有明显影响。
