DPG Phi
Verhandlungen
Verhandlungen
DPG

Regensburg 2019 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 32: Charged Soft Matter, Polyelectrolytes and Ionic Liquids I

CPP 32.13: Vortrag

Mittwoch, 3. April 2019, 12:45–13:00, H13

Local and long-range dynamics of ionic liquids: A 1H and 19F NMR-study — •Elisa Steinrücken, Manuel Becher, and Michael Vogel — TU Darmstadt, Institut für Festkörperphysik, Hochschulstr. 6, 64289, Darmstadt, Germany

Room Temperature Ionic Liquids (RTIL) are salts with a low melting point and vapour pressure. They are usually glass forming systems with complex and heterogeneous molecular dynamics. The combination of different cations and anions opens wide ranges of chemical and physical applications and their optimization. Hence, a fundamental understanding of molecular dynamics is of crucial importance. Here, imidazolium-based RTILs with a [Tf2N] anion are in the experimental focus, with a variation of the alkyl chain length at the cation to increase structural heterogeneities. Nuclear Magnetic Resonance (NMR) provides access to glassy dynamics in wide ranges of time and length scales. Due to its isotope selectivity the dynamical behaviour of different molecules/molecular groups can be separated. In a static field gradient, we measure the self-diffusion coefficient of the cation (1H) and anion (19F). Field-Cycling relaxometry provides frequency-dependent relaxation times T1(ω). The structural relaxation can be identified using support from concomitant molecular dynamics simulations. The resulting rotational correlation times are in good agreement with the findings of dynamic light scattering. Comparing long-range self-diffusion with short-range structural relaxation, we analyse cation-anion couplings, in contrast to literature no decoupling due to structural changes is observed.

100% | Mobil-Ansicht | English Version | Kontakt/Impressum/Datenschutz
DPG-Physik > DPG-Verhandlungen > 2019 > Regensburg