The contribution of different molecular interaction potentials to the chemical potential of ionic liquid ions in various chemical environments

• Antragsteller: Professor Dr. Ingo Krossing; Professor Dr.-Ing. Jorg Thöming
• Fachliche Zuordnung: Chemische und Thermische Verfahrenstechnik
• Förderung: Förderung von 2008 bis 2012
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 92382694

In this project we propose the prediction of physicochemical parameters of dissolved ionic liquids, based solely on their structure. Due to the rapid development of ILs we need to understand and predict their behavior in aqueous technical and environmental systems. To achieve this we have chosen a reliable model based on a poly-parameter linear free energy relationship (pp-LFER) including ionic-interaction descriptors. In addition we calculated the same set of descriptors using COSMO-RS (conductor like screening model) and compared them with the experimentally determined cation descriptors. Using both calculated and experimental descriptors, we were able to predict the octanol-water partitioning coefficient, water solubility, and critical micelle concentration of ILs, as well as the activity coefficient and hydrophobicity of the anion in the water-octanol system. However the accuracy of the predictions is dependant on the water content of the IL/water system being analyzed. In this proposal we aim to determine and quantify this water dependence on the LFER descriptors. We aim to determine and quantify the charge (z) of the LFER equation. The current set of descriptors is inter-dependant, meaning the calculated and experimental values cannot be mixed. However, we propose the creation of non-interdependent set of descriptors, which can thereby be partially determined experimentally and mathematically. This would allow for greater flexibility and would vastly increase the applicability and relevance of the method to answer fundamental questions about the interaction of ILs molecules in aqueous systems, as well as applied problems concerning the environmental fate and hazard assessment of IL.

• DFG-Verfahren: Schwerpunktprogramme
• Teilprojekt zu: SPP 1191: Ionische Flüssigkeiten