Berlin 2015 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 13: Focus: Field Controllable Functional Polymers II

CPP 13.3: Talk

Monday, March 16, 2015, 15:30–15:45, C 264

Magnetic gels - The influence of the sample shape on the deformation behaviour — •Rudolf Weeber and Christian Holm — Institut fuer Computerphysik, Allmandring 3, 70569 Stuttgart

Magnetic gels are hybrid materials, consisting of magnetic particles immearsed in a hydrogel or elastomer. They are of interest due to the intricate interplay between elastic and magnetic forces observed in them. For example, magnetic gels can change their elasticity and shape, when an external magnetic field is applied. This property makes them interesting for applications in medicine and engineering.

It has been shown that two mechanisms exist by which a magnetic gel can deform in a homogeneous magnetic field. The first one is present only in magnetic gels in which the magnetic particles act as the cross-linker. It relies on a coupling of the orientation of the magnetic nanoparticles to the polymer matrix. The second mechanism, which will be the focus of this contribution, is based on the change of the average dipole-dipole interaction between the nanoparticles as they align to an external field.

Here, we discuss a recently developed coarse-grained simulation model for magnetic gels to study this deformation mechanism. It allows us to examine both, the influence of the local configuration of magnetic nanoparticles and the shape of the entire gel sample on the material's deformation in an external magnetic field.