G.Auernhammer: 3D investigations of field induced deformations in magnetic hybrid materials

Description

The aim of the project is to study the deformation of the matrix around magnetic particles (internal deformation) in magnetic hybrid materials under the influence of magnetic and mechanic fields. In the project we head for fundamental understanding of the material through static and dynamic measurements.

• What is the precise mechanism that leads from local deformations and reorganizations to changes in the mechanical properties of the hybrid material?
• What is the relation between the macroscopic (external) and the internal deformation of the hybrid material?

In the framework of the SPP 1681, we focus on the experimental determination of the matrix and its deformation using confocal fluorescent microscopy.
Fluorescently labeled tracer particles in the matrix will be followed in space and time. From this information we deduce the internal deformation of the matrix under the influence in of external fields. Magnetic fields act exclusively on the embedded magnetic particles and exert torques and forces on them. Due to these forces and torques the magnetic particles move and rotate relative to the matrix and thus deform the matrix. These micro-structural changes should be correlated to changes in the mechanic properties of the material. To do so we combine fluorescent confocal microscopy with mechanical measurements (piezo-rheology and nano indentation) of the sample under external load.
      
Top: Image of magnetic particles (black) embedded in a marix of fluorescently labeled particles (green). Bottom: Measuring the deformation of the matrix through particle tracking.

© Auernhammer

Project Manager

Prof. Dr. Günter K. Auernhammer, MPIP Mainz

Staff

Henrik Schmidt, MPIP Mainz

Grant period

2013 -

Publications

[1] Collin, D., Auernhammer, G. K., Gavat, O., Martinoty, P., Brand, H. R.; Frozen-in magnetic order in uniaxial magnetic gels: preparation and physical properties; Macromol. Rapid Comm. 24 (2003), 737 - 741.
[2] Auernhammer, G. K., Collin, D., and Martinoty, P.; Viscoelasticity of suspensions of magnetic particles in a polymer: Effect of confinement and external field; J. Chem. Phys. 124 (2006), 204907 1 -10.
[3] Roth, M., Schilde, C., Lellig, P., Kwade, A., and Auernhammer, G. K.; Colloidal aggregates tested via nanoindentation and simultaneous 3D imaging; Eur. Phys. J. E 35 (2012), 9801.

Contact

Max-Planck-Institut für Polymerforschung
Ackermannweg 10
55128 Mainz

Internet

http://www2.mpip-mainz.mpg.de/~auhammer/