title: Metal fluoride-based transparent nanocomposites with low refractive indices.
abstract: The utilisation of magnesium and aluminium fluoride nanoparticles in the preparation of transparent composites leading to materials with superior properties was investigated. Nanoscopic magnesium and aluminium fluoride has been prepared by the fluorolytic sol-gel route from the alkoxides and was surface modified by the reaction with trifluoroacetic acid or perfluorobutyric acid. IR spectroscopic experiments of the xerogels and crystal structure analysis of a trinuclear [Mg3(μ3F)(μ-TFA)6(OCH3)2(py)](3-) cluster unit indicate that the carboxylate group is bound to the particle surface in a monodentate or bidentate bridging fashion. These particles were successfully incorporated into acrylate polymers with up to 40 wt% content to give fully transparent material. Ellipsometry and m-line measurements of thin films show the reduction of the refractive index of composite films with increasing metal fluoride filler content.
authors: Humboldt-Universität zu Berlin, Department of Chemistry, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
authors: Johannes
authors: J
authors: Noack
authors: Carsten
authors: C
authors: Fritz
authors: Clemens
authors: C
authors: Flügel
authors: Felix
authors: F
authors: Hemmann
authors: Hans-Jürgen
authors: HJ
authors: Gläsel
authors: Olaf
authors: O
authors: Kahle
authors: Christian
authors: C
authors: Dreyer
authors: Monika
authors: M
authors: Bauer
authors: Erhard
authors: E
authors: Kemnitz