Berlin 2015 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 2: Focus: Field Controllable Functional Polymers I

CPP 2.8: Talk

Monday, March 16, 2015, 12:00–12:15, C 264

Viscoelastic properties of magneto-sensitive elastomers — •Dmytro Ivaneyko, Vladimir Toshchevikov, and Marina Saphiannikova — Leibniz-Institut für Polymerforschung Dresden e.V.

Magneto-sensitive elastomers (MSEs) are smart materials which consist of micron-sized magnetic particles dispersed within a non-magnetic elastomeric matrix. Mechanical properties of MSEs change considerably under external magnetic field [1]. In the present study we consider viscoelastic properties of isotropic MSEs using a coarse-grained cubic network model, which describes the network dynamics in the low-frequency regime [2]. Equations of motion for magnetic particles take into account topology of the elastic network and magnetic interactions between the particles. We show that the application of uniform magnetic field leads to the splitting of the relaxation spectrum into two branches for the motions of the particles parallel and perpendicular to the field. The shear dynamic moduli G' and G'' of MSEs are calculated as functions of the frequency. The values of G' and G'' are shown to depend on the direction of the shear deformation with respect to the magnetic field. For instance, both G' and G'' increase if the shear is applied perpendicular to the direction of the magnetic field. This prediction is in a qualitative agreement with existing experimental data.

[1] D. Ivaneyko et al., Soft Matter 10 (2014), 2213.

[2] V.P. Toshchevikov et al., Macromolecules 42 (2009), 3417.