Regensburg 2007 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 19: POSTER: Micro and Nano Fluidics

CPP 19.17: Poster

Mittwoch, 28. März 2007, 16:00–18:30, Poster B

Free Standing Filaments Formed by Bent-shaped Molecules — •Alexandru Nemes, Alexey Eremin, and Ralf Stannarius — Institute of Experimental Physics, University of Magdeburg, Universitätsplatz 2, D-39106 Magdeburg, Germany

In few mesophases of bent-shaped liquid crystals, stable free standing filaments can be prepared with slenderness ratio (length to diameter ratio) of more than 1000 (Jákli et al. 2003). Their bundle-like structure was found with help of X-Ray, AFM, SEM and optical measurements [1]. In previous experiments it has been observed that the filaments respond with a lateral deflection to a strong DC electric field applied perpendicular to the filament axis. This technique was used as an excitation method to pluck the filaments and forced them, when the DC field was removed, to damped oscillations. The model we used to describe these free oscillations helps us to understand which forces are dominant in such liquid chords [2]. To understand the nature of the electric forces on the filaments, AC electric fields are applied perpendicular to the filament axis. The analysis of the Fourier transformed response of the filament oscillations reveals the functional interactions of the electric field with the material.

[1] A.Nemes, A.Eremin, R.Stannarius, M.Schulz, H.Nádasi, W.Weissflog, Phys.Chem.Chem.Phys., 2006, 8, 469

[2] R.Stannarius, A.Nemes, A.Eremin, Phys. Rev. E, 2005, 72,020702