Electrical interaction between two spherical particles covered by an ion-penetrable charged membrane Original Research Article

The electrical interaction between two spherical particles, each comprises a rigid uncharged core and an ion-penetrable (porous) charged membrane, in an electrolyte solution is examined. The Poisson equation governing the spatial variation of electrical potential is solved by the Greenʹs function approach, and the interaction energy of the system under consideration evaluated. Several approximate analytical expressions for the interaction energy are derived. We show that if the membrane is thick, and/or the electrical double layer is either very thin or very thick, a particle can be treated as a porous one, and the linear superposition approach often adopted in the literature becomes appropriate.