Berlin 2008 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 21: POSTERS Colloids, Nanoparticles and Aggregates

CPP 21.6: Poster

Mittwoch, 27. Februar 2008, 16:00–18:30, Poster A

Dissipative Structure Formation in Surfactant Films — •Peter C. Seitz and Motomu Tanaka — Physikalisch Chemisches Institut, INF 253, 69120 Heidelberg, Universität Heidelberg

We study the formation of dissipative microstructures in composite ultrathin surfactant films. Dissipation occurs at the three phase contact line during Langmuir-Blodgett transfer onto a solid substrate of lipid/lipopolymer films. Structures are stripe like and continuous over several cm, limited only by substrate size. Stripe to stripe distance is precisely controlled by transfer speed from several µm to below optical resolution.

The onset of the meniscus is observed using imaging ellipsometry. This allows the determination of the microscopic contact angle as well as the discrimination between domains in lateral direction. Data is analyzed using Off-Null ellipsometry and repeating null ellipsometry conditions giving access to Å scale resolution over a µm range. The close relation between the contact angle and the draining process during transfer allows a hydrodynamic modelling and thus a deeper insight to the nucleation leading to stripe patterns.