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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 47: Focus: Charge Effects in Soft and Biological Matter III (jointly with BP)

CPP 47.5: Vortrag

Freitag, 26. März 2010, 11:30–11:45, H45

Diffusion and charge transport in ionic liquids: the role of ion-ion interactions — •Joshua Sangoro, Ciprian Iacob, Jörg Kärger, and Friedrich Kremer — Institute of Experimental Physics I, University of Leipzig, Linnéstr. 5, 04103, Leipzig

Self-diffusion in a variety of glass-forming ionic liquids (ILs) are investigated in a wide frequency and temperature range by means of Broadband Dielectric Spectroscopy(BDS) and Pulsed Field Gradient Nuclear Magnetic Resonance (PFG NMR). It is experimentally shown that in the time-scale characterising the cross-over from sub-diffusive to diffusive ion dynamics, the hopping lengths are of the order of molecular diameters determined from quantum-chemical calculations. This provides a direct means - via Einstein-Smoluchowski relation - to determine diffusion coefficients by BDS over more than 8 decades unambiguously and in quantitative agreement with independent PFG NMR measurements. Unprecedented possibilities in the study of charge transport and dynamic glass transition are thus opened.