Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 18: Poster: Polymer Dynamics
CPP 18.20: Poster
Dienstag, 12. März 2013, 18:15–20:15, Poster C
Huge material transport in azobenzene polymer films induced by highly intense laser light of 534 nm — •zahra molla1, regina rosenhauer2, joachim stumpe2, and ullrich pietsch1 — 1Universität Siegen, Festkörperphysik,Siegen, Germany — 2FHI für Angewandte Polymerforschung, Potsdam, Germany
Photochemical polymers undergo permanent trans to cis isomerisation under illumination with UV or visible light. In the past this property has been used to generate surface relief lattices via illumination of thin films of an azobenzene polymer, for example, by an interference pattern of polarized light. For this purpose typically Ar+ lasers emitting at 488nm with power < 250mW have been used. Meanwhile new lasers, such as disc lasers emitting at 534nm, are available with beam power up to 2W. In order to study light induced nano-movement, a thin film of the photopolymer Holomix5 was irradiated under normal incidence by an expanded beam of the disc laser. The induced change in film height has been probed by He-Ne laser (633nm) under an angle of 30o. Recorded by a photo diode the reflected intensity shows dramatic changes while illumination. The intensity increases immediately by several percent switching the disc laser with power > 500mW on followed by intensity oscillation with time period of few seconds. The intensity drops back to the initial values switching the disc laser off. The number of oscillations depends on laser power. The scattering data are interpreted in terms of Fresnel equations and refer to the creation of a column formed by polymer material with height up to several 100nm and column diameter equal to that of the laser beam.