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DY: Fachverband Dynamik und Statistische Physik
DY 26: Ferrofluids / Liquid crystals
DY 26.10: Vortrag
Donnerstag, 29. März 2007, 12:45–13:00, H3
Synthesis and magnetoviscosity of nanotube/nanorod ferrofluids — •Zhenyu Wu1, Dörte Junk2, Xiong Liu3, Alexander Bittner3, Christina Wege4, and Carl Krill1 — 1Institute of Micro and Nanomaterials, Ulm University, D-89081 Ulm — 2Technical Physics, University of the Saarland, D-66123 Saarbrücken — 3Max Planck Institute for Solid State Research, D-70569 Stuttgart — 4Institute of Molecular Biology and Virology of Plants, D-70550 Stuttgart
As colloidal suspensions of ferromagnetic nanoparticles in a carrier liquid, ferrofluids combine the magnetic properties of solids with the flow properties of liquids. Their viscosity increases dramatically in the presence of an externally applied magnetic field; however, this magnetoviscosity is lost when the ferrofluid is subjected to shear forces. One strategy to suppress such shear thinning is to replace the spherical nanoparticles of a conventional ferrofluid with nanotubes or nanorods. We report the synthesis of nanotube ferrofluids based on the metallization of the tobacco mosaic virus (TMV) with Co. The magnetoviscous properties of these samples were studied using a squeeze-flow viscometer at magnetic fields up to 150 mT and frequencies up to 400 Hz. The measured viscosity behavior is compared to that of conventional ferrofluids and to suspensions of Fe nanorods prepared by aerosol condensation.