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CPP: Chemische Physik und Polymerphysik
CPP 25: POSTER Electronic Structure and Spectroscopy
CPP 25.22: Poster
Donnerstag, 30. März 2006, 17:00–19:00, P2
Photo induced aging of polymers — •Knut Morawetz1, Burkhard Stiller1, Jaroslav Ilnytskyi1, Dieter Neher1, Stefan Katholy1, Ronald Ries2, and Asta Richter2 — 1University of Potsdam, Institute of Physics, Am Neuen Palais 10, D-14469, Germany — 2University of Applied Sciences, Engineering Physics Section, Bahnhofstraße ,15745 Wildau, Germany
The photo induced aging of freshly prepared azobenzene films is studied. It was found that under illumination the film undergoes essential changes in both its mechanical and optical properties. In the first illumination cycle, an abnormal response was observed. At first, the layer stiffness increased, afterwards the film becomes softer. However, a long time (24h) illumination leads to a strong increase of both hardness and stiffness as well as to the change of the film colour. The experiments were performed using different techniques. The method of nano indentation was used to obtain the absolute values for the E modulus and for a hardness of films, these data were compared with the measurements for the stiffness and thickness made by AFM with high lateral resolution. Optical properties, in particular the absorption and refractive index were measured by UV-VIS spectroscopy and ellipsometry.