ORGANIC FLUORESCENT DYES IN ORGANICALLY MODIFIED AL2O3-SIO2 OR TIO2-SIO2 COATINGS WITH VARYING POLYMETHYLMETHACRYLATE CONTENT

Fluorescence and photostability of organic fluorescent dyes incorporated in organically modified Al2O3-SiO2 and TiO2-SiO2 (ormocer) coatings were examined with the aim of combining the fluorescence properties of Lumogen F dyes [G. Seybold and G. Wagenblast, Dyes Pigments 11 (1989) 303] in PMMA with the advantages of a more rigid ormocer matrix and the good coating properties of ormocer solutions. Dissolved PMMA was added to the ormocer to study the influence of an increasing PMMA content, in particular on the UV stability of the dye. The degree of polymerisation of the organic component was observed by IR spectroscopy. Thin fluorescent coatings with good optical qualities allow the preparation of fluorescent light concentrators with high concentration ratios for diffuse light, which is interesting for example in solar applications.