| abstract |
Sol-gel process for producing a photochromic composite material, in which there is a precursor and a photochromic complex; the process includes successive stages of hydrolysis, condensation, and drying, in which: —an alkoxysilane is selected as a precursor, and a ruthenium complex with a nitrosyl ligand is selected as a photochromic complex, and, in combination, —the sol-gel process is implemented starting from the selected precursor and photochromic complex, with successive stages of hydrolysis, arrangement in a container of a selected shape, condensation, curing and aging, whereby this latter stage includes a final drying cycle, and—for the curing and aging stages—the pH, temperature and duration are selected so that in the produced xerogel, whose shape is determined by that of the container, the photochromic ruthenium complex with a nitrosyl ligand, in the crystalline state and in the form of nanoparticles, is inserted into the nanopores of the silica matrix, distributed in an at least substantially homogeneous way. |