Coarse-grained simulations of charge, current and flow in heterogeneous media

We present a coarse-grained simulation method for complex charged systems. This mesoscopic model couples a hydrodynamic description to a free energy functional accounting for the interactions between solvent(s) and charged solutes. It is implemented in a hybrid lattice-based algorithm, whereby the evolution of the overall mass and momentum is taken care of via a Lattice Boltzmann scheme, whereas the composition and ionic concentrations are updated using the link-flux method. Several applications illustrate the power of this coarse-grained model for charged heterogeneous media: the transport of charged tracers in charged porous media, the deformation of an oil droplet in water under the effect of an applied electric field, and the distribution of ions at an oil–water interface as a function of their affinity for both solvents.