Dresden 2011 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 34: Poster: Elastomers and Gels

CPP 34.13: Poster

Mittwoch, 16. März 2011, 17:00–19:00, P2

Magnetic field dependent optical transmission of ferrogels with Ni nanorods as magnetic phase — •Etienne Wagner, Philipp Bender, Andreas Tschöpe, and Rainer Birringer — Universität des Saarlandes, Saarbrücken, Deutschland

Uniaxial ferromagnetic single-domain Ni nanorods with diameters < 64 nm and aspect ratios > 3 were synthesized by electrodeposition of Ni into porous alumina templates. They were released by dissolution of the alumina matrix in aqueous sodium hydroxide solution (NaOH) containing additionally polyvinyl-pyrollidone (PVP) as surfactant. After a thorough washing procedure the nanorods were dispersed in bidistilled water, and mixed into gelatine solutions at 60°C. Applying a homogenous magnetic field while cooling down the solution to room temperature results in uniaxial ferrogels, where the nanorods are mechanically linked to the polymer network. When the surrounding gel matrix is soft enough, a magnetic torque enables the rotation of the nanorods in field direction. In the present study the elastic response of the Ni nanorods to an external homogenous magnetic field is analyzed via optical transmission. In particular, the rotation angle of the nanorods in field direction was determined dependent on the magnitude of the applied field for different particle densities, gelatine concentrations and gelation times.