Electrostatically swollen lamellar stacks and adiabatic pair potential of highly charged platelike colloids in an electrolyte

We show that describing the screened electrostatic interactions in a period ic stack of rigid parallel identical charged platelike colloids within a lo cal density functional theory approach generically leads to a swelling beha vior. Within the same framework, we find that the effective potential betwe en a pair of such plates immersed in an electrolyte is repulsive at all dis tances. This general result is in contradiction with a theory put forward b y Sogami, Shinohara, and Smalley, that we criticize and thoroughly reconsid er to show how the two approaches can be reconciled.