Self-consistent Field Theory of Ionic Fluids. Grand Canonical Ensemble Formulation.

In this chapter, we continue the formulation of statistical field theory for ionic fluids using the grand canonical ensemble approach. This approach allows us to take into account the excluded volume of ions and to derive the modified Poisson-Boltzmann equations that describe the system more accurately. Additionally, the grand canonical framework makes it easier to formulate a variational field theory that takes into account ionic correlations beyond the mean-field approximation, which was introduced in Chap. 1.