Ionic Liquids and Aqueous Solutions

Surface sensitive X-ray scattering experiments can provide an important link between the molecular structure of electrolytes and their ion distribution on free surfaces and buried interfaces. Time-resolved experiments allow us to follow the relaxation dynamics of anions and cations near the electrode after applying an external potential with sub-millisecond resolution.
At the free liquid surface of ILs composed of cations with long aliphatic side chains, we observed surface induced smectic order. This near surface structure exists over a wide temperature range and extends over several tenth of nanometers into the liquid bulk. The lamellar ordering can significantly affect the dynamics of molecules adjacent to the liquid phase boundary by acting as diffusion barrier. Therefore, understanding the formation mechanism of the observed interfacial structures will help to increase the performance in supported ionic liquid phase (SILP) catalysis.