title: Buckling of paramagnetic chains in soft gels.
abstract: We study the magneto-elastic coupling behavior of paramagnetic chains in soft polymer gels exposed to external magnetic fields. To this end, a laser scanning confocal microscope is used to observe the morphology of the paramagnetic chains together with the deformation field of the surrounding gel network. The paramagnetic chains in soft polymer gels show rich morphological shape changes under oblique magnetic fields, in particular a pronounced buckling deformation. The details of the resulting morphological shapes depend on the length of the chain, the strength of the external magnetic field, and the modulus of the gel. Based on the observation that the magnetic chains are strongly coupled to the surrounding polymer network, a simplified model is developed to describe their buckling behavior. A coarse-grained molecular dynamics simulation model featuring an increased matrix stiffness on the surfaces of the particles leads to morphologies in agreement with the experimentally observed buckling effects.
authors.affiliation: Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany. auhammer@mpip-mainz.mpg.de.
authors.forename: Shilin
authors.initials: S
authors.lastname: Huang
authors.affiliation: Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Pessot
authors.affiliation: Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany.
authors.forename: Peet
authors.initials: P
authors.lastname: Cremer
authors.affiliation: Institute for Computational Physics, Universität Stuttgart, 70569 Stuttgart, Germany.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Weeber
authors.affiliation: Institute for Computational Physics, Universität Stuttgart, 70569 Stuttgart, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Holm
authors.affiliation: Chair of Magnetofluiddynamics, Measuring and Automation Technology, Institute of Fluid Mechanics, Technische Universität Dresden, 01069 Dresden, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Nowak
authors.affiliation: Chair of Magnetofluiddynamics, Measuring and Automation Technology, Institute of Fluid Mechanics, Technische Universität Dresden, 01069 Dresden, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Odenbach
authors.affiliation: Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany.
authors.forename: Andreas M
authors.initials: AM
authors.lastname: Menzel
authors.affiliation: Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany. auhammer@mpip-mainz.mpg.de.
authors.forename: Günter K
authors.initials: GK
authors.lastname: Auernhammer