Orthokinetic aggregation of charged colloidal particles in the presence of repulsive double layer force: A trajectory analysis with the solution of non-linear Poisson–Boltzmann equation
Orthokinetic aggregation of charged colloidal particles in the presence of repulsive double layer force: A trajectory analysis with the solution of non-linear Poisson–Boltzmann equation
复制标题
带电胶体粒子在双层排斥力存在下的正交运动聚集：非线性泊松解的轨迹分析
DOI：
10.1016/j.colsurfa.2015.07.037
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Y Adachi
中科院分区：
文献类型：
--
作者：
T Sugimoto;M Kobayashi;Y Adachi
我们研究了在不同 KCl 浓度下，表征良好的羧基封端乳胶颗粒的湍流凝固速率与 pH 值的函数关系。所研究颗粒的负电荷增加，因此随着 pH 值的增加而产生双电层排斥力。基于 Derjaguin、Landau、Verwey 和 Overbeek 理论的轨迹分析，利用电荷调节边界条件下的非线性 Poisson-Boltzmann (PB) 方程的解，分析了 pH 依赖性凝血速率，其中表面电势等静电边界条件取决于表面分离距离。应该指出的是，这是第一次尝试将计算结果与表面电荷对湍流凝聚速率影响的实验数据进行比较。使用轨迹分析的计算可以很好地描述实验数据。然而，为了获得实验数据和计算之间良好的一致性，我们需要随着KCl浓度的增加而减小Hamaker常数AH。盐浓度的依赖性可能归因于范德华引力的起源本质上是分子之间的静电偶极子-偶极子相互作用。也就是说，我们认为随着盐浓度的增加，范德华吸引力越来越受到离子电荷的屏蔽。
We studied turbulent coagulation rates of well-characterized carboxyl-terminated latex particles as a function of pH at different KCl concentrations. The negative charge of the studied particles increases and thus develops the electrical double layer repulsion with increasing pH. The pH-dependent coagulation rate was analyzed on the basis of the trajectory analysis with the Derjaguin, Landau, Verwey, and Overbeek theory using the solution of non-linear Poisson–Boltzmann (PB) equation under the charge regulation boundary condition, in which the electrostatic boundary conditions such as surface potential depends on surface separation distance. It should be noted that this is the first attempt to compare the calculated results with the experimental data of the effect of surface charge on turbulent coagulation rates. The calculation using the trajectory analysis can well describe the experimental data. However, to obtain the good agreement between the experimental data and the calculation, we need to decrease the Hamaker constantAHwith increasing KCl concentration. The dependence ofAHon salt concentration is probably ascribed to the fact that the origin of the van der Waals attraction is essentially electrostatic dipole–dipole interaction between molecules. That is, we consider that the van der Waals attraction is increasingly screened by the charge of ions with increasing salt concentration.