Dresden 2014 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 29: Colloids and Complex Liquids I
CPP 29.2: Vortrag
Mittwoch, 2. April 2014, 09:45–10:00, ZEU 114
Influence of electric and magnetic fields on colloidal suspensions of anisometric pigment particles — •Kathrin May1, Alexey Eremin1, Susanne Klein2, and Ralf Stannarius1 — 1Otto-von-Guericke Universität, FNW/IEP/ANP, 39106 Magdeburg, Germany — 2HP Laboratories, Long Down Avenue, Stoke Gifford, Bristol BS34 8QZ, UK
Suspensions of anisometric nanoparticles show a wide range of interesting characteristics, like their concentration dependent phase behavior and response to electric and magnetic fields. Specifically the electro- and magneto-optical switching by aligning the colloidal particles in electric or magnetic fields makes them good candidates for the development of new devices.
The investigated colloidal particles are rod-shaped commercial pigment particles stabilized with a polymer and suspended in dodecane. They have an aspect ratio of about 5. This anisometry leads to the formation of ordered phases at concentrations above 15 wt%. In electric AC fields, the suspension can be electrically switched. In addition, the alignment of the colloidal particles in a magnetic field is investigated. For the pure suspension, very high magnetic fields in the range of 25 T are necessary. To increase the response to magnetic fields the suspensions are doped with magnetic nanoparticles. This is expected to reduce the critical magnetic field strength needed to align the pigment particles.