Berlin 2008 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 20: POSTERS Driven Soft Matter
CPP 20.31: Poster
Mittwoch, 27. Februar 2008, 16:00–18:30, Poster A
Transitions of Smectic Systems under Shear Investigated by Nuclear Magnetic Resonance — Bruno Medronho1,2, Shahram Shafaei3, Gönül Ar3, Michael Blaschke3, Ulf Olsson2, and •Claudia Schmidt3 — 1Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal — 2Physical Chemistry 1, Center of Chemistry and Chemical Engineering, Lund University, Box 124, 221 00 Lund, Sweden — 3Department of Chemistry, University of Paderborn, Warburger Str. 100, 33098 Paderborn, Germany
Smectic phases driven by shear show interesting structural transitions. Most interesting is the formation of monodisperse, close-packed, multilamellar vesicles (MLVs), also called onions, that is found in many lyotropic lamellar phases [1]. Other systems show transitions between different orientations of planar layers, when parameters such as shear rate or temperature are changed. These dynamic transitions, which can be continuous or discontinuous, have been investigated by deuterium NMR spectroscopy [2]. Results for the shear-induced formation and destruction of MLVs in an aqueous solution of the nonionic surfactant C10E3 will be presented [3].
[1] O. Diat, D. Roux, and F. Nallet, J. Physique IV, 3, 193 (1993).
[2] S. Müller, Claus Börschig, Wolfram Gronski, Claudia Schmidt, and D. Roux, Langmuir, 15, 7558 (1999).
[3] B. Medronho, S. Shafaei, R. Szopko, M. G. Miguel, U. Olsson, C. Schmidt, in preparation.