Berlin 2005 – wissenschaftliches Programm

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DY: Dynamik und Statistische Physik

DY 14: Complex Fluids

DY 14.10: Vortrag

Freitag, 4. März 2005, 17:45–18:00, TU H3010

Preparation and Characterization of Capped Colloids.* — •Florian S. Merkt, Artur Erbe, and Paul Leiderer — Universität Konstanz

Colloids have been used to study interparticle and particle-wall interactions on the micron scale. Here we present a technique to fabricate colloids with a large variety of surface materials. This controlled design of surface properties enables us to investigate an even broader range of interactions than was covered by previous experiments.
In particular we prepare aqueous suspensions of capped colloids in which half of the surface is covered with a metal layer. Mono- and multilayers of magnetic and unmagnetic metals are evaporated onto micron-sized Silica spheres. By adjusting the layer structure the magnitude and direction of the magnetic moments can be tuned.
The particles’ magnetic properties are characterized and their behavior in light and magnetic fields is observed. Further experiments to investigate adhesion forces and interactions in close contact between colloidal and plane surfaces are proposed. Especially the detachment dynamics of colloidal particles with various surface properties sticking to a surface will be investigated.

*Supported by the DFG through SFB 513