The Chemistry and Physics of Ionic Liquids
Per Jacobsson, Department of Applied Physics

Ionic liquids (ILs) are low-temperature melting salts, forming liquids comprised solely of cations and anions. ILs have so far mainly been explored for replacing volatile solvents in organic synthesis, but also the fundamental physics of these materials start to attract the interest of a wide scientific audience. Special interest is given to the relationships between the non-existent vapour pressure, the viscosity, the Coulomb interactions, and the diffusion of species in various types of ionic liquid based materials. Recently, ILs have been suggested for usage in energy storage and energy conversion technologies [Science 302 (2003) 422-425]. Proton conducting ILs may be used in polymer based fuel cells - one strong alternative to the combustion engine for the transportation sector. The knowledge of these materials is hitherto very rudimentary, but there is a current upsurge in scientific activity. Also application of ILs in energy storage technology has been suggested, by mixing an IL with a lithium salt an electrolyte useful for state-of-the-art lithium batteries can be obtained. Such batteries, with other types of electrolytes, are today found in most high-tech electronics, but a material break-through may make batteries competitive to enter the consumer market for small cars, motorcycles and power tools. The use of an IL-based electrolyte can be the necessary step, but there are outstanding technological as well as fundamental challenges. This project will focus on the fundamental physical properties of ILs on a molecular scale. Insight will be given by advanced molecular modelling techniques, using national supercomputer facilities, and via combinations of different light (IR, Raman, PCS etc) and neutron scattering techniques, together accessing different time- and length-scales of structure and dynamics. The neutron experiments will be carried out at large-scale facilities in Europe. The graduate student should preferably have a strong background in physics or physical chemistry for a fully characterisation-oriented project or in chemistry for a project aimed also at synthesis of new ILs to further characterise. Both an interest in mediating results to an audience and a sincere commitment to address energy related materials are required.