Dynamics of Probes in Ionic Liquids from Ultrafast to Ultraslow
Room temperature ionic liquids have been known for fascinating physicochemical properties and have been extensively studied in the last two decades. They are considered to be a solution for the future’s green chemistry strategies. The tunability of their structure to obtain a desired property for a specific application and the possibility of one trillion ionic liquids including their binary and ternary mixtures explain why ionic liquids are called designer solvents. A deep microscopic level understanding of the structure and dynamics of ionic liquids and their mixtures with common solvents is necessary for their use in variety of applications and in their improvement. To contribute to this aim, ultrafast and ultraslow dynamics of some imidazolium based ionic liquids in liquid and in glassy regimes were investigated using optical Kerr effect spectroscopy and fluorescence recovery after photobleaching techniques. Ionic liquids are unique materials also in terms of their structure and dynamics. The ionic liquids in this study are known for their structural heterogeneity, by the formation polar and nonpolar regions, in the liquid state and their dynamical heterogeneity in the liquid and glassy state. Our studies on mixtures of polar and nonpolar solute molecules with ionic liquids show that localization of solute molecules is determined by the intermolecular interactions. Slow dynamics of ionic liquids were found to be quite similar to that of simple fragile glass formers and the dynamic heterogeneity in these systems near the glass transition is strongly dependent on the cation-anion combinations.Embargo status: Restricted to TTU only. TTU community may view by logging in with their eRaider (top right). Others my request access by click on the PDF link to the left.