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Dynamics of photoinduced orientational order of azo‐dyes in polymer films
Author(s) -
El Osman Ahmad,
Dumont Michel
Publication year - 1999
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19991370114
Subject(s) - photoisomerization , materials science , polyimide , dichroism , copolymer , poling , relaxation (psychology) , anisotropy , photochemistry , polymer , polymer chemistry , optoelectronics , isomerization , optics , chemistry , nanotechnology , composite material , catalysis , organic chemistry , psychology , social psychology , physics , layer (electronics) , dielectric , ferroelectricity
Dynamical and spectral behavior of photoassisted electrical poling and photoinduced anisotropy are studied in films of DR1‐doped PMMA, DR1‐PMMA copolymer and new DR1‐Polyimide copolymer. The orientational mobility of DR1 is characterized both in ordering processes (angularly selective trans‐cis photoisomerization) and in disordering relaxation processes. Mobility is increased by the photoisomerization and decreases slowly with time, after the end of optical pumping. The transient dichroism recorded simultaneously on six probe wavelengths shows a spectral inhomogeneity of the absorption band of DR1 and of the photoinduced anisotropy (particularly in polyimide films).