Dielectric spectroscopy of ion pairing and ion clustering in mixtures of ionic liquids with molecular solvents

• Applicant: Professor Dr. Hermann Weingärtner
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2006 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 29179964

The project aims at characterizing the static and frequency-dependent dielectric permittivity of neat low-viscosity room-temperature ionic liquids and their mixtures with solvents of low polarity. Experiments for mixtures will be conducted over the entire composition range from dilute solutions to the neat ionic liquids, thus covering the transition of typical electrolyte solution behavior to molten salt behaviour. The experiments will provide information on the dynamics of ions and the formation, ordering and dynamics of ion pairs and larger ion clusters. Zerofrequency extrapolation of the dielectric permittivity will provide the static dielectric constant, which for electrically conductive systems is not accessible by conventional methods. The static dielectric constant is a key quantity for assessing the polarity of a solvent and an important input quantity for modellings of thermodynamic and transport coefficient data.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1191: Ionic Liquids