Three-Dimensional Double Layers

Electrical double layers are ubiquitous; they will inevitably emerge, given mobile charge carriers and an interface. They play a decisive role in well-known problems such as electrochemical reactions, electrokinetics, and colloidal stability and thus have been studied extensively since the very concept of the double layer was postulated by Helmholtz. Furthermore, the transition between different lateral arrangements of counter and co-ions during electrification of narrow pores has been observed in simulations and shown to greatly affect both the capacitance and dynamics of the double layers. These relatively new issues and developments all point to new challenges in understanding the three-dimensional (3D) structures of the double layers controlled by the electrification of surfaces. The new feature of the double layer in ionic liquids is that structural transitions can take place in the adjacent layer to the electrode, even when its ions may not be specifically adsorbed on the electrode.