Electrostatic Interaction between Dissimilarly Charged Membranes in Salt-Free Solution

Abstract

A theoretical study on the electrostatic interaction between the dissimilarly charged membranes in a salt-free solution has been presented in this paper. The results show that the electric double-layer force is always repulsive for positively charged planar surfaces regardless of surface charge density (or potential) and separation; however, a long-range attraction is observed between surfaces with unequally opposite charge densities. Such attractive force also exists and is independent of the separation when both surfaces carry unequally opposite potential.