Dresden 2014 – wissenschaftliches Programm

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

DF: Fachverband Dielektrische Festkörper

DF 23: Glasses and Glass Transition I (Joint Session with CPP and DY)

DF 23.3: Vortrag

Donnerstag, 3. April 2014, 12:30–12:45, ZEU 114

Glassy dynamics and physical aging in fucose saccharides as studied by Infrared- and Broadband Dielectric Spectroscopy — •Wilhelm Kossack¹, Karolina Adrjanowicz², Magdalena Tarnacka¹, Wycliffe Kiprop Kipnusu¹, Mateusz Dulski², Emanuel Urandu Mapesa¹, Kamil Kaminski², Sebastian Pawlus², Marian Paluch², and Friedrich Kremer¹ — ¹Universität Leipzig, Linnestr.5, Molekülphysik, 04103 Leipzig, Germany — ²Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice, Poland

Fourier Transform InfraRed (FTIR) and Broadband Dielectric Spectroscopy (BDS) are combined to study both, the intra- and inter-molecular dynamics for two isomers of glass forming fucose, far below and above the calorimetric glass transition temperature, T_g. It is shown, that the various IR-active vibrations exhibit in their spectral position and oscillator strength quite different temperature dependencies, proving their specific signature in the course of densification and glass formation. The coupling between intra- and inter-molecular dynamics is exemplified by distinct changes of IR active ring vibrations far above the calorimetric glass transition temperature at about 1.16 T_g, where the dynamic glass transition (α relaxation) and the secondary β relaxation merge. — For samples physically annealed below T_G slower isothermal relaxation times than extrapolated from liquid state are observed .