Influence of the relative orientation of two charged anisotropic colloidalparticles on their electrostatic coupling: A (N,V,T) Monte Carlo study

Monte Carlo simulations are performed in the Canonical ensemble to determin e the equilibrium configurations of the counterions and co-ions in the vici nity of two charged hard disks at fixed separations. Derivation of the elec trostatic energy and the ionic configurational entropy is used to determine the relative stability of two charged platelets as a function of their sep aration and relative orientation. An effective pair potential is derived fr om the free energy variation and may be used in the framework of the one co mponent plasma to model suspensions of charged platelets. Finally, the vari ation of the free energy of two charged colloids in the presence of salt ma y be reproduced by Yukawa potential with a residual charge equal to 7% of t he nominal electric charge of the colloids.