Current understanding of ions and charged surfactants at aqueous solid interfaces

In this chapter, we review the recent progress in our understanding of the solid/liquid interfacial structure in terms of density variations, water orientation and surface charge. We discuss the effects of the interfacial water structure on the adsorption of charged species on charged and uncharged surfaces, focusing on graphene and silica as typical examples of hydrophobic and hydrophilic surfaces, respectively. First, we present the interfacial structure obtained from force-field-based molecular dynamics simulations and discuss how the results compare to experimental, theoretical and other simulation studies. Second, we demonstrate how the simulated dielectric profile and ion-specific potentials are incorporated into the Poisson–Boltzmann equation. As an example, we study the effects of surface charge density, salt concentration and ion type on the double-layer electrostatics at a silica surface.