Hauptseminar Porous Media SS 2021/Magnetic gels

Date

2021-07-16

Time

15:30

Topic

Magnetic gels as smart materials

Speaker

Patrick Egenlauf

Tutor

Patrick Kreissl

Contents

Magnetic nano- or mircronsized particles embedded in polymeric environments are an interesting class of composite materials. As the magnetic properties of the particles couple to the (visco)elastic properties of the surround polymeric matrix, one can dynamically control some of the composite material's properties, such as their motion, shape, and even anisotropic mechanical stiffness, through an external magnetic field. Magnetic elastomers have been connected to a variety of possible applications including actuation, sensing, "artificial muscle", microrobotics, bio-medical applications …

This talk should start with a introduction to magnetic particles, susceptibility, single particle magnetization, Langevin susceptibility, and, including dipolar interactions, ferrofluids. Then MD modeling strategies for magnetic gels will be presented in two and three dimensions, showing how an external field can lead to anisotropic deformation of the gel.

Literature

• Rudolf Weeber, Melissa Hermes, Annette M. Schmidt, Christian Holm.
  Polymer architecture of magnetic gels: a review.
  Journal of Physics: Condensed Matter 30(6):063002, 2018.
  [DOI]
• Rudolf Weeber, Marco Klinkigt, Sofia Kantorovich, Christian Holm.
  Microstructure and magnetic properties of magnetic fluids consisting of shifted dipole particles under the influence of an external magnetic field.
  The Journal of Chemical Physics 139(21):214901, 2013.
  [DOI]
• K. Butter, P. H. H. Bomans, P. M. Frederik, G. J. Vroege, A. P. Philipse.
  Direct observation of dipolar chains in iron ferrofluids by cryogenic electron microscopy.
  Nature Materials 2:88–91, 2003.