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CPP: Chemische Physik und Polymerphysik

CPP 12: Colloids and Nanoparticles II

CPP 12.3: Vortrag

Montag, 8. März 2004, 16:15–16:30, H 39

Electrophoretic investigations of surface-modified silica nano-particles — •Holger Reiber and Thomas Palberg — Johannes Gutenberg-Universität, Institut für Physik, Staudingerweg 7, D-55099 Mainz

Because of strong coulombic interactions, dispersions of electrostatically stabilised colloidal silica particles show a characteristic behaviour in the case of very low salt conditions. The strength of the interactions between the single particles is a function of the surface charge, and therefore, it also influences electrophoretic properties as for example the particle mobility. For this reason, we investigate silica nano-particles which we synthesised using a variation of the Stöber-syntheses by means of laser Doppler velocimetry. The particles differ from each other only with respect to number and/or type of the ionic surface groups, but not with respect to typical properties such as diameter, density or polydispersity. For this reason, our measurements can show the influence of a variable surface charge on system properties of nano-particles such as the mobility.