POLARITY STUDIES ON ORMOSILS USING A SOLVATOCHROMIC FLUORESCENT-PROBE

Ormosils (organically modified siloxanes) are a relatively new family of materials, prepared by the sol-gel method, with properties that are intermediate between those of glasses and polymers. To probe the micr opolarity of various solvents and ormosils, a ketocyanine dye (KC) wit h unique solvatochromic properties in fluorescence was used. KC is an excellent probe and is sensitive to the polarity of its microenvironme nt. Fluorescence studies revealed remarkable changes in the fluorescen ce band positions or intensities as a function of the polarity of the ormosil, which depend on the different ormosil precursors used. Storag e stability was also investigated.