Berlin 2008 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 5: New Materials
CPP 5.8: Vortrag
Montag, 25. Februar 2008, 12:00–12:15, C 230
Phases Sequences of a Gelatine Based Physical Gel at Low Temperatures — •Martine Philipp1, Ulrich Müller1, Claude Lecomte2, Emmanuel Wenger2, Roland Sanctuary1, Jörg Baller1, Bartosz Zielinski1, Patrick Alnot2, Didier Rouxel2, and Jan Krüger1 — 1LPM, Université du Luxembourg, Luxembourg — 2Université Nancy, Nancy, France
Only little is known about the low temperature properties of physical gels like gelatines dissolved in glycerol/water. Because of the inherent disorder of the gelatine molecules, depending on the cooling scenario different equilibrium and non-equilibrium low temperature states can be created. Taking Kaisers glycerol gelatine (Merck) as a model substance we will demonstrate that the low temperature behaviour of this gel is very interesting. Different stable glassy states have been found including that of a glass-ceramic. The latter is usually created by thermo diffusion (Soret effect) and grows in form of ball-like structures. Brillouin spectroscopy, X-ray scattering and optical microscopy are used to identify the different low temperature phases. An interpretation for the growth of the ball-like ceramic objects based on the Soret effect is proposed. The results are compared with the low temperature properties obtained for pure glycerol/water mixtures. In addition, the influence of inorganic nanoparticles on the phase formations within Kaisers glycerol gelatine is discussed.