Regensburg 2007 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 26: Ferrofluids / Liquid crystals
DY 26.6: Talk
Thursday, March 29, 2007, 11:45–12:00, H3
The deformation of a ferrogel in uniform magnetic fields — •Christian Gollwitzer1, Alexander Turanov2, Marina Krekhova3, Ingo Rehberg1, Günter Lattermann3, and Reinhard Richter1 — 1Experimentalphysik V, Universität Bayreuth — 2Zavoisky Physical-Technical Institute. KSC, RAS, Kazan, Russia — 3Makromolekulare Chemie I, Universität Bayreuth
Ferrogels are an interesting new class of materials that enhance the properties of magnetic fluids by elastic components. Ferrogels are able to exert forces when exposed to magnetic field gradients [1]. But also in homogeneous fields there can be shape changes, albeit much smaller ones. This has been predicted already by Landau [2] for the case of a sphere. We expose a sphere of a thermoreversible magnetoelastic material [3] to a homogeneous magnetic field and observe the elongation laterally with a highspeed camera. To compensate the deformation of the sample under gravity, we immerse it into water. We compare the outcome of this magnetic stress experiment to mechanical creep experiments and to the theoretical predictions by Landau [2] and Raikher [4].
[1] Zrinyi, M., Barsi, L., Szabo, D. & Kilian, H.-G. 1997
The Journal of Chemical Physics 106 (13), 5685–5692.
[2]Landau, L. D. & Lifschitz, E. M. 1960 Electrodynamics of Continuous
Media, 3rd edn., vol. 8. Oxford: Pergamon.
[3]Lattermann, G. & Krekhova, M. 2006 Macromol. Rapid Commun. 27, 1373–1379.
[4]Raikher, Y. & Stolbov, O. 2005 Journal of Applied Mechanics and
Technical Physics 46 (3), 434–443.