Berlin 2001 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 16: Poster: Dynamics of Molecular Systems, Polymer Dynamics, Glass Transition, Crystallization, Electronic Properties of Polymers
CPP 16.15: Poster
Montag, 2. April 2001, 12:30–15:00, AT1
Structure and dynamics in thermoreversible ferroelectric liquid crystalline gels — •Jan Prigann1, Christian Tolksdorf2, Holger Skupin1, Rudolf Zentel2, and Friedrich Kremer1 — 1University of Leipzig, Fak. for Physics and Geoscience, Linnest. 5, D-04103 Leipzig — 2University of Mainz, Inst. of Organic Chemistry, Duesbergweg 10-14, D-55099 Mainz
Time-resolved FTIR spectroscopy with polarized light is used to study the segmental structure and mobility in ferroelectric liquid crystalline molecules embedded in thermoreversible gel networks of different crosslinking densities. By that the different orientations of the molecular segments in their dependence from the external electric field strength are analysed. It is found that the formation of the gel network can be described to a first approximation by an elastic potential. [1,2]. This stabilises a slightly non-planar structure and leads to an asymmetry in the reorientation behaviour: in order to obtain one of the two possible planar states a sufficient DC electric field has to be applied which is lower for the one state compared to the other. A further asymmetry is found if the reorientation times between the two planar states are regarded. The comparison of gels that are prepared with different gel former concentrations allows to study the influence of the network density on the reorientation times and the reorientation angles.
References [1] Shilov, S.; Gebhard, E; Skupin, H.; Zentel, R.; Kremer, F.; Macromol., 32; 1570-1575; (1999) [2] Skupin, H.; Kremer, F.; Shilov, S.V.; Stein, P.; Finkelmann, H.; Macromol.; 1999; 32; 3746-3752