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DY: Dynamik und Statistische Physik
DY 33: Ferrofluids and Liquid Crystals
DY 33.6: Vortrag
Montag, 7. März 2005, 15:15–15:30, TU H2032
Small angle neutron scattering study of the magnetoviscous effect in ferrofluids — •Loredana Mirela Pop1, Stefan Odenbach1, and Albrecht Wiedenmann2 — 1ZARM, University of Bremen — 2HMI Berlin
The increase of the viscosity of ferrofluids, by means of moderate magnetic fields, the so called magnetoviscous effect, can be used for different technological applications like, for example, in active dampers. However, due to a strong shear thinning in commercially available ferrofluids, the viscosity changes diminish for technical useful shear rates to values that are not suitable for applications. Thus, an optimisation by development of new types of ferrofluids exhibiting stronger changes of the viscosity with the magnetic field and a higher shear stability of the effects is required. Therefore, a better understanding of the microscopic mechanisms of the magnetoviscous effect is essential. The results of the investigation of the microstructure of ferrofluids using small angle neutron scattering as well as of the corresponding rheological investigations will be presented. In addition, the comparison between experimental results and theoretical approaches will provide the information that is necessary for a detailed understanding of the magnetoviscous effects allowing the synthesis of suited ferrofluids for innovative applications in the future.