Dresden 2009 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 28: POSTERS Interfaces and Thin Films
CPP 28.15: Poster
Mittwoch, 25. März 2009, 17:00–19:00, P3
Effect of geometrical confinement and surface charge on the structuring in colloidal silica suspensions — •Yan Zeng1, Sabine Klapp2, and Regine v.Klitzing1 — 1Stranski-Laboratorium für Physikalische & Theoretische Chemie, Institut für Chemie, TU Berlin — 2Institut für Theoretische Physik, Freie Universität Berlin
This work focuses on the effect of geometric confinement on the structuring of colloidal suspensions in thin film geometry. Colloidal silica suspensions with different particle concentration and ionic strength allow a deeper insight into the ion distribution around the particles. Results from colloidal probe atomic force microscopy (CP-AFM) force-distance measurements in films are compared with results from small-angle X-ray scattering (SAXS) in bulk. It is found that the characteristic lengths obtained from force oscillation measured by AFM, correlate well with the intermediate particle distance from the structure peak measured by SAXS, scale with particle concentration with an exponent of -1/3. In order to study the effect of the surface elasticity the bare silicon surfaces are modified by polymer coatings. The effect on the structuring of particles is measured by AFM and compared with our preliminary results from Thin Film Pressure Balance (TFPB).