Regensburg 2002 – wissenschaftliches Programm
SYPF 2.6: Poster
Donnerstag, 14. März 2002, 09:00–18:00, Poster B
Cascade instability of hole formation in dewetting films — •Jürgen Becker1, Günther Grün1, Ralf Seemann2, Karin Jacobs2, and Ralf Blossey3 — 1Abt. Angewandte Mathematik, Uni Bonn — 2Abt. Angewandte Physik, Uni Ulm, Albert-Einstein-Allee 11, 89069 Ulm — 3SuNyx Surface Nanotechnologies GmbH, Stolberger Strasse 370, D-50339
We report on a combined experimental, theoretical, and simulation effort to quantitatively describe the formation of satellite holes at the rim of a hole that has opened up in a dewetting process in a polystyrene film. Satellite holes appear at the circumference of the initial hole by a cascade instability, giving rise to a complex local structure of the film. In order to uncover the mechanism behind this structuring process we have, first, performed experiments on PS films with varying thickness. Second, the systems have been quantitatively characterised by determining the effective interface potential, the free energy per unit area of the flat PS film as a function of its thickness. Third, a linear stability analysis of the depression region surrounding the opening hole defines a new, discrete spinodal wavelength as a function of film thickness. Fourth, based on the lubrication approach we have performed extensive simulations of film rupture utilising newly developed convergent simulation algorithms.