A comparison between micro- and macro-structure of magnetoactive composites

A possibility to determine the microstructure of magneto active composites using micro-computed tomography (?-CT) [1] was investigated in this work. The main interest of the current study has been an observation of the magnetic field dependent shift of individual particles from their initial positions inside an elastomeric matrix. For this purpose a ?-CT system has been combined with a sample holder coupled with two permanent magnets, enabling the investigation of the micro-structure under influence of an external homogeneous field. In the experimental investigations samples based on carbonyl iron particles have been used. The particles have been dispersed in a polymeric matrix and the polymer has been created in the presence of a magnetic field driving structure formation of the particles. After the characterization of the sample in its initial state, i.e. without external stimuli, it has been subjected to the magnetic field and its internal structure has been once more studied by ?-CT. As a result a comparison of the macroscopic change of the sample structure and the particle displacement could be undertaken.