Regensburg 2016 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 27: Poster: Soft Matter Dynamics / Glasses
CPP 27.7: Poster
Dienstag, 8. März 2016, 18:15–21:00, Poster B2
Extracting material net properties of monomolecular coverages from broadband dielectric spectroscopy measurements with nano-structured electrode arrangements — •Martin Tress1,2, Nils Neibauer2, Rene Winkler3, Petra Uhlmann3, Emmanuel Mapesa2, Manfred Reiche4, and Friedrich Kremer2 — 1Max Planck Institute for Polymer Research, Mainz — 2University of Leipzig — 3Leibniz-Institut für Polymerforschung Dresden e.V. — 4Max Planck Institute of Microstructure Physics, Halle (Saale)
Recently, Broadband Dielectric Spectroscopy (BDS) has been combined with a nano-structured electrode arrangement to investigate glassy dynamics in monomolecular layers and isolated polymer chains [1]. Thereby, insulating nano-structures serve as spacers between the silicon electrodes enabling an electrode separation of only 40 nm. Since this is still larger than the height of the actual sample material, a major fraction of the capacitor volume is empty. Consequently, the measured signal is an average of several contributions, including the dielectric properties of the sample itself, the spacer material and the gap between the electrodes. Due to the particular geometry, the composition of these contributions is not straight-forward. To unravel the individual dielectric functions of all components an equivalent circuit model is employed. Using BDS spectra of poly(2-vinylpyridine) (P2VP) brushes and condensed isolated P2VP chains as examples it is demonstrated how to unravel molecular relaxations, polarization effects and charge transport as well as the extraction of their net properties.
[1] M. Tress et al. Science 341 (2013) 1371