Interactions between a particle covered by an ion-penetrable charged membrane and a charged surface: A modified Gouy-Chapman theory

摘要

The interaction between a colloidal particle and a surface plays an important role in various interfacial phenomena in both industrial and biological processes. Previous efforts are mainly based upon a point-charge model where the effect of the sizes of all the charged species is neglected. Here, we consider the case where a particle is covered by an ion-penetrable charged membrane, which mimics a biological entity, by taking this effect into account. We show that the sizes of the charged species are in the estimation of the electrical interaction force between particle and surface; the general trend of the result obtained is consistent with the experimental observations reported in the literature. The effects of the following key factors on the energy barrier for the particle-surface interaction are examined: the surface potential, the fixed charge density and the thickness of membrane layer, and the sizes of charged species. [References: 25]