1Sorbonne University, France
Interfaces are ubiquitous in ionic liquids applications. However, due to the absence of solvent, and to the dense Coulomb nature of ionic liquids, it is not possible to apply the conventional double-layer picture to describe them. Many experimental techniques were therefore developed to probe the structure and dynamics of these interfaces, such as AFM, SFA, reflectivity, etc. In parallel, theory and simulations were extended in order to provide a molecular scale interpretation of the results. These studies have shown that the interface between ionic liquids and solid substrates can exhibit properties that are not simple reflections of surrounding bulk materials. The nature of the adsorbed layer(s) also changes tremendously from one ionic liquid to another. During this keynote I will provide an historical perspective on the topic, and discuss the numerous challenges that remain to be addressed. I will particularly focus on the case of electrified interfaces which are important for energy applications.