title: Controlled production of ZnO nanoparticles from zinc glycerolate in a sol-gel silica matrix.
abstract: The controlled production of ZnO nanoparticles within an amorphous silica matrix is achieved using a new methodology consisting of four stages. First, precursor zinc glycerolate nanoparticles are produced within reversed micelles of glycerol in heptane stabilized by the surfactant Aerosol-OT (bis-ethylhexyl sodium sulfosuccinate, AOT). The surface of these nanoparticles is then modified by exchanging AOT with bis-trimethoxysilyl-ethane (BTME). The surface-modified nanoparticles are copolymerized with tetramethoxysilane (TMOS) to provide a composite silica material, in which the nanoparticles are apparently dissolved, producing a uniform distribution of zinc in the silica matrix. Finally, the conversion of zinc to ZnO is achieved by heating the material at 700 degrees C, leading to a uniform dispersion of very small (<10 nm) ZnO particles within the amorphous matrix. The fluorescence spectrum of the ZnO particles within the matrix is blue-shifted, as expected from the strong quantum confinement achieved. The properties of the system at all stages in this synthetic process are monitored using TEM, XRD, fluorescence and FT-IR spectroscopy. Glycerol forms complexes with many metal ions, so the present procedure may be generalized to provide uniform distributions of metal ions and subsequently metal oxide nanoparticles in amorphous silica.
authors.affiliation: Department of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus.
authors.forename: Rodoula
authors.initials: R
authors.lastname: Moleski
authors.forename: Epameinondas
authors.initials: E
authors.lastname: Leontidis
authors.forename: Frank
authors.initials: F
authors.lastname: Krumeich
mesh_terms: D004655:Emulsions / Q000138:chemical synthesis / Q000737:chemistry; D005782:Gels / Q000737:chemistry; D005990:Glycerol / Q000737:chemistry*; D008823:Micelles; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D015032:Zinc / Q000737:chemistry*; D015034:Zinc Oxide / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D004655:Emulsions; D005782:Gels; D008823:Micelles; D012822:Silicon Dioxide; D015032:Zinc; D005990:Glycerol; D015034:Zinc Oxide