Publications

Export 3 results:
Sort by: [ Author  (Asc)] Title Type Year
A B C [D] E F G H I J K L M N O P Q R S T U V W X Y Z   [Show ALL]
D
Davim, E. a, M. H. V. a Fernandes, and R. C. C. b Monteiro. "Glass-ceramics produced from incinerated municipal solid waste." Glass Technology: European Journal of Glass Science and Technology Part A. 48 (2007): 164-167. AbstractWebsite

A homogeneous black coloured glass was obtained by melting the bottom ashes produced by a municipal solid waste incinerator at 1300°C for 2 h without any chemical additives. Based on thermal analysis data glass-ceramics were produced by heat treating the glass, doped with additional TiO2 as a nucleating agent, at temperatures between 870 and 1000°C. The crystalline phases precipitated during the heat treatments were identified by powder XRD and the microstructures were examined using SEM. After a heat treatment at 900°C for 2 h, the glass was converted into a fine grained glass-ceramic with uniform microstructure. The major crystalline phases precipitated in the glass-ceramics were augite (Ca(Mg,Fe)Si2O6), gehlenite (Ca2Al2SiO7) and clinopyroxene (Ca(Ti,Mg,Al)(Si,Al)2O6). Preliminary evaluation of the mechanical and chemical properties of the bottom ash glasses and glass-ceramics suggest that they have potential to compete with existing natural and commercial outdoor cladding materials.

Drasovean, R. a, R. b Monteiro, E. b Fortunato, and V. c Musat. "Optical properties of cobalt oxide films by a dipping sol-gel process." Journal of Non-Crystalline Solids. 352 (2006): 1479-1485. AbstractWebsite

Cobalt oxide thin films were prepared by using the dipping sol-gel process. The films were deposited onto glass slides, starting from methanolic solution of cobalt acetate Co(CH3COO)2 · 4H2O. The effects of film thickness and sol concentration on structural and optical properties were studied. Structural analyses of Co3O4 films were performed by X-ray diffraction. The film thickness was varied by using different withdrawal speeds and the number of dipping-heating cycles. It was found that the grain size increases with the number of dipping N. The results point out to some compacting effect that increases with the number of dippings: the films exhibit direct and indirect optical transition, absorption coefficients are of the order of 104 cm-1, and upon annealing the absorption coefficient increases. © 2006 Elsevier B.V. All rights reserved.

Drasovean, R. a, R. b Monteiro, and M. c Cherif. "Structure and morphology study of cobalt oxide doped silica nanocomposite films." AIP Conference Proceedings. Vol. 1203. 2010. 483-488. Abstract

Cobalt oxide doped silica films were synthesized by a dip-coating technique. Initial compounds were cobalt acetate Co(CH3COO)2-4H 2O and tetraethoxysilane Si(OC2H5)4. The chemical composition was studied by X-ray diffraction and UV-Vis spectroscopy. The morphology analyses were carried out by means of atomic force microscopy. The average diameter of cobalt oxide dispersed particles increases with the molar ratio Co:Si and with the aging time of the initial colloidal solution. © 2009 American Institute of Physics.