Berlin 2001 – scientific programme

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CPP: Chemische Physik und Polymerphysik

CPP 19: Poster: New Methods, Thin Polymer Films, Monolayers

CPP 19.32: Poster

Thursday, April 5, 2001, 12:30–15:00, AT1

Correlation between the dipole moment and the dielectric behavior during the isomerization of azobenzene moieties in a polymeric matrix — •Andreas Fritz¹, Andreas Schoenhals¹, Michael Rutloh², and Joachim Stumpe² — ¹Bundesanstalt fuer Materialforschung und -pruefung, Unter den Eichen 87, D-12205 Berlin — ²Institut fuer Duennschichttechnologie und Mikrosensorik e.V., Eriseering 42, D-10319 Berlin

Photochromic polymers are interesting materials for different optical applications such as data storage. It is known that optical anisotropy can be induced in addition to photochroism if the samples are irradiated by polarized light. The actual mechanism of that process which must be related to molecular mobility is still poorly understood. Therefore dielectric investigations during irradiation as function of time and temperature were carried out on a series of different polymers. The time dependence of the dielectric properties can be described by a single exponential function. To get molecular parameters like the dipole moment for the azobenzene dye molecules quantum chemical calculation were conducted. A comparison between the calculated dipole moments of the dye molecules and the change of the dielectric permittivity caused by the E/Z-isomerization shows a direct correlation.