CoarseGrained Modeling of Charged Colloidal Suspensions: From PoissonBoltzmann Theory to Effective Interactions
Abstract
Electrostatic interactions between macroions largely govern the equilibrium thermodynamic and dynamical properties of chargestabilized colloidal suspensions and polyelectrolyte solutions. Predicting the properties of such complex, multicomponent systems with accuracy sufficient to guide and interpret experiments requires realistic modeling of the interparticle interactions and collective behavior of manyparticle systems. While the fundamental interactions may be simple, the sheer number of particles and the broad ranges of length and time scales confront the modeler with significant computational challenges. A general strategy for mitigating such challenges is to "coarse grain" or "integrate out" the degrees of freedom of some components, reducing the original multicomponent model to a simpler model of fewer components. The tradeoff for so reducing complexity is that the simpler model is governed by modified (effective) interparticle interactions. This chapter is a "howto" manual for implementing coarsegraining methods to derive effective electrostatic interactions in systems of charged macroions. After reviewing the cell model implementation of the PoissonBoltzmann theory of charged colloids and polyelectrolytes, we describe an alternative implementation, based on perturbation theory. From a linear response approximation, we derive effective electrostatic interactions for chargestabilized suspensions of spherical colloids.
 Publication:

arXiv eprints
 Pub Date:
 December 2012
 arXiv:
 arXiv:1212.1758
 Bibcode:
 2012arXiv1212.1758D
 Keywords:

 Condensed Matter  Soft Condensed Matter
 EPrint:
 14 pages, 4 figures, In Electrostatics of Soft and Disordered Matter, D. S. Dean, J. Dobnikar, A. Naji, and R. Podgornik, Eds., Proceedings of the CECAM Workshop "New Challenges in Electrostatics of Soft and Disordered Matter" (Pan Stanford, 2013)