Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Photochromic hybrid sol-gel coatings: Preparation, properties, and applications

: Klukowska, A.; Posset, U.; Schottner, G.; Wis, M.L.; Salemi-Delvaux, C.; Malatesta, V.

Materials science 20 (2002), Nr.1, S.95-104
ISSN: 0137-1339
ISSN: 1068-820X
Fraunhofer ISC ()
inorganic-organic hybrid polymer coating; fast photochromic response; photochromic activity; photochromophore; hydrolysate; organofunctional alkoxysilane; doping; thermal curing; sol-gel material; graftable derivative; rigidity; thin film; mechanical property; pure host material; glass substrate; plastic substrate; photochemical degradation; artificial weathering; fatigue behaviour

Inorganic-organic hybrid polymer (ORMOCER(R)) coatings with a fast photochromic response and high photochromic activity were: prepared by incorporation of the photochromophore Variacrolo Blue D into hydrolysates of organofunctional alkoxysilanes, with subsequent thermal curing. Besides the traditional way of doping the sol-gel materials by physically dissolving the dye, a graftable derivative was prepared and covalently attached to two matrices of different rigidity. The resulting thin films showed good photochromic activity, no blooming, mechanical properties at least comparable to the pure host material, and can be applied to different glass and plastic substrates. Photochemical degradation was studied by means of artificial weathering and factors influencing the fatigue behaviour of the coatings assessed. The graftable dye showed improved photochemical fatigue resistance. The more rigid matrix was preferable, too, in terms of photodegradation.