Berlin 2012 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 14: Poster: Glasses I (jointly with DY)
CPP 14.4: Poster
Dienstag, 27. März 2012, 18:15–20:15, Poster A
Heat capacity spectroscopy of the dynamic glass transition in chosen room temperature ionic liquids — •Evgeni Shoifet1, Heiko Huth1, Sergey Verevkin2, and Christoph Schick1 — 1University of Rostock, Institute of Physics, 18051 Rostock, Germany — 2University of Rostock, Institute of Chemistry, 18051 Rostock, Germany
Many of the ionic liquids are good glass formers. Nevertheless, only a few studies of the glass transition in ionic liquids are available so far. Particularly the frequency dependence of the dynamic glass transition (alpha-relaxation) is not known for most ionic liquids. The standard technique for such studies - dielectric spectroscopy - is not easily applicable to ionic liquids because of the high electrical conductivity. The aim of this study is to use different calorimetric techniques to obtain complex heat capacity and to investigate the dynamic glass transition of room temperature ionic liquids (RTILs) in a wide frequency range. This can give an insight in cooperative motions of ions and ion clusters in RTILs. The techniques that were used are DSC, TMDSC, and AC-chip calorimeter covering a total range of 0.001-10000 Hz. The trace of the dynamic glass transition in the activation diagram for RTILs was fitted to the Vogel-Fulcher-Tammann-Hesse function and the parameters compared for different RTILs.