Regensburg 2007 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 19: POSTER: Micro and Nano Fluidics

CPP 19.2: Poster

Mittwoch, 28. März 2007, 16:00–18:30, Poster B

Dewetting dynamics of thin polymer films on topographic and elastic substrates — •Konstantina Kostourou, Krishnacharya Khare, Martin Brinkmann, Stephan Herminghaus, and Ralf Seemann — Max Planck Institute for Dynamics and Self-Organization, D-37073 Göttingen, Germany

Dewetting dynamics of polymer films in triangular grooves and on elastic substrates are studied experimentally and theoretically. Liquid filaments, in triangular grooves, with convex liquid-vapor interface are unstable and undergo dynamic instability resulting in equally spaced individual droplets with a preferred distance. This instability is driven by the local variation of the Laplace pressure with filament width and resembles a generalized Rayleigh-Plateau instability. From the time scale of the dynamic instability we extract slip properties of the polymer/substrate interface. Additionally we study the dewetting dynamics of thin polymer films on rubber elastic substrates. Here, the dynamics are additionally determined by the dissipative properties of the elastic substrate. We compare the flow behavior of liquid polymer films on substrates of different visco-elasticity and constant wettability. Our experiments show that dewetting is faster on substrates with larger elastic modulus.