The solution to a general PBE is non-The electrostatic interaction between two particles covered by an trivial, except for limited cases. The degree of difficulty ion-penetrable charged membrane suspended in an a:b electrolyte depends largely on the geometry of a charged surface, the solution is estimated. A perturbation method is employed to solve types of electrolyte in the liquid phase, and the boundary the governing nonlinear Poisson-Boltzmann equation. The apconditions on the surface. In practice, either drastic assumpproximate analytical expression derived for potential distribution tions are made and a simplified PBE is solved, or it is solved yields a sufficiently accurate estimate. Both the stability ratio and numerically.
the critical coagulation concentration of the counterions of the
Previous efforts on the estimation of the stability ratio of system under consideration are derived. The results of a numerical a dispersed system were mainly based on rigid surfaces (e.g., simulation reveal that the stability ratio decreases with an increase in the size of a particle and increases with the total amount of 3-5). Although this model is appropriate for most of the fixed charges in the membrane phase. For a constant total amount inorganic colloids, it can be unrealistic for some of the disof fixed charges and particle size, the stability ratio increases with persed entities in practice. These include biocolloids and a decrease in the thickness of the membrane. We show that monoparticles covered by an artificial membrane (6-11). A typidispersed particles are more stable than polydispersed particles. cal example of the former is human erythrocytes, the periph-