Berlin 2012 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 1: Interfaces and Thin Films I

CPP 1.6: Talk

Monday, March 26, 2012, 11:00–11:15, C 130

Light-induced wrinkling and moving gratings in low-molecular azo films — Philipp Gruner, Michael Arlt, and •Thomas Fuhrmann-Lieker — Makromolekulare Chemie und Molekulare Materialien, Universität Kassel

The dynamics of mass transport in thin layers of a low molecular glass containing azo chromophores are studied in two experiments.

First, spinodal wrinkling of a multilayer system consisting of the azo glass confined by a rigid substrate and an elastic cover layer is induced by light. The time evolution of the wrinkle structures is measured and compared to thermal wrinkling. Application of theoretical models allows the determination of the viscoelastic properties in the non-equilibrium fluid.

Second, in a dynamic holographic experiment surface corrugation gratings are shifted by phase control of the generating beams. The relaxation timescale in which the corrugation pattern can follow the moving light field is measured.

With these experiments, fundamental properties of photofluidic thin films such as irradiation-dependent viscosity are addressable.