Ground state of two unlike charged colloids: An analogy with ionic bonding
Max-Planck-Institut für Polymerforschung - Ackermannweg 10, 55128, Mainz, Germany
Corresponding author: email@example.com
Accepted: 22 June 2000
In this letter, we study the ground state of two spherical macroions of identical radius, but asymmetric bare charge . Electroneutrality of the system is ensured by the presence of the surrounding divalent counterions. Using Molecular Dynamics simulations within the framework of the primitive model, we show that the ground state of such a system consists of an overcharged and an undercharged colloid. For a given macroion separation the stability of these ionized-like states is a function of the difference () of neutralizing counterions and . Furthermore the degree of ionization, or equivalently, the degree of overcharging, is also governed by the distance separation of the macroions. The natural analogy with ionic bonding is briefly discussed.
PACS: 82.70.Dd – Colloids / 61.20.Qg – Structure of associated liquids: electrolytes, molten salts, etc / 41.20.-q – Applied classical electromagnetism
© EDP Sciences, 2000