Berlin 2008 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 11: DRG-DPG SYMPOSIUM Rheology III

CPP 11.3: Vortrag

Dienstag, 26. Februar 2008, 10:30–10:45, C 264

Rheo-NMR Studies of Liquid Crystals in Shear Flow — Gönül Ar, Shahram Shafaei, and •Claudia Schmidt — Department Chemie, Universität Paderborn, Warburger Str. 100, 33098 Paderborn, Germany

Nuclear magnetic resonance spectroscopy has proven a useful tool for the investigation of shear-induced phenomena in liquid crystals [1,2]. Due to the anisotropy of the interactions of nuclear spins, information about shear-induced orientations can be obtained. In deuterium NMR, the quadrupolar interaction is used to probe the orientation of the liquid crystalline director. In situ observations of director orientations under shear can reveal the microscopic origin of macroscopic rheological phenomena. Recent examples for deuterium NMR investigations of shear phenomena in different types of liquid crystals, such as nematic, lamellar and hexagonal phases will be presented.

[1] P. T. Callaghan, Rep. Prog. Phys., 62, 599 (1999).

[2] C. Schmidt, in: Modern Magnetic Resonance, Vol. 3, Springer, New York, 2006.