Dresden 2006 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 12: POSTER Colloids, Nanoparticles and Self-Organizing Systems
CPP 12.11: Poster
Dienstag, 28. März 2006, 17:00–19:00, P3
Control of forces in aqueous wetting nanofilms — •Katarzyna Ciunel1 and Regine v. Klitzing2 — 1Stranski-Laboratorium, TU Berlin, Str, d, 17. Juni 112, D-10623 Berlin — 2Institut für Physikalische Chemie, CAU Kiel, Ludewig-Meyn-Strasse 8, D-24118 Kiel
The (de)stability and functionality of thin liquid films plays an important role for processes in technical applications, like foaming, emulsification and flotation. The forces between the opposing interfaces depend on the composition of the film interfaces and of the film fluid. In the present paper the sum of interactions between the film surfaces is determined quantitatively by the disjoining pressure isotherm (disjoining pressure vs. film thickness) and it is measured by varying the outer pressure in a so-called thin film pressure balance. The approach of a solid substrate to one film interface (wetting film: air/water/solid) changes the drainage behaviour with respect to a free-standing film (foam film). In order to modify the interactions between the fluid and the interface in a wetting film the solid surface is pre-coated with polyelectrolytes of different charge and viscoelasticity. The air/water interface is varied by the adsorption of different amphiphiles. The results give a clear evidence for negative charges at the free air/water interface.