Polymeric Precursor
Mostrando 13-24 de 84 artigos, teses e dissertações.
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13. Nano and Micro Ceramic Membranes from Degradable Templates
Abstract The nano/microstructures with highly porous surface area have attracted tremendous attention, particularly the synthesis and tailoring of porous and hollow materials of high performance. In this paper, an easy method of cost-effective synthesis of hollow ceramic fiber membranes based on Hydroxyapatite, TiO2 and ZrO2 stabilized with Yttrium, is propo
Mat. Res.. Publicado em: 28/07/2016
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14. NON-CRYSTALLINE COPPER OXIDE HIGHLY DISPERSED ON MESOPOROUS ALUMINA: SYNTHESIS, CHARACTERIZATION AND CATALYTIC ACTIVITY IN GLYCEROL CONVERSION TO ACETOL
Polymeric precursor method and wet impregnation route were applied to synthesize copper and aluminium-based catalysts in order to obtain a material with interesting properties in catalytic reactions. The changes in the structural, morphological and textural properties due to the choice of preparation method were characterized by different techniques, such as
Quím. Nova. Publicado em: 2016-07
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15. Spectroscopic Properties of pigment Li2-xZn1-xPrxTi3O8
Inorganic compounds doped with rare earths (Ce3+, Pr3+, Nd3+, Sm3+, Eu 3+, Gd 3+, Tb 3+, Tm3+) have been used in various applications including light-emitting devices such as fluorescent lamps, cathode ray tubes, lasers and inorganic pigments. In this study, Pr3+ is doped in spinel Li2ZnTi3O8 system and synthesized by the polymeric precursor method, which is
Mat. Res.. Publicado em: 14/06/2016
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16. P(VDF-TrFE)/ZrO2 Polymer-Composites for X-ray Shielding
Poly(vinylidene fluoride – tryfluorethylene) [P(VDF-TrFE)] copolymers were mixed with zirconia nanoparticles. The investigation was conducted with the intention to produce nanocompounds with potential to be used as protective patient shielding in radiological procedures. Polymer based nanocomposites with 1, 2, 3, 5 and 10 wt% of ZrO2 nanoparticles were pre
Mat. Res.. Publicado em: 26/02/2016
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17. The Multiple Faces of Eugenol. A Versatile Starting Material and Building Block for Organic and Bio-Organic Synthesis and a Convenient Precursor Toward Bio-Based Fine Chemicals
Phenylpropenes are produced by plants as part of their defense strategy against microorganisms and animals, and also as floral attractants of pollinators. Eugenol, the main component of clove’s essential oil, is an inexpensive and easily available phenylpropene that has been known by humankind since antiquity, and used as a medicinal agent, but also for fo
J. Braz. Chem. Soc.. Publicado em: 2015-06
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18. Synthesis and characterization of polyarylacetylene for use in the monolithic vitreous carbon processing
In this work, polyarylacetylene (PAA) prepolymer obtained from 1,4-diethynylbenzene was evaluated as polymeric precursor of monolithic vitreous carbon (MVC). The monomer 1,4-diethynylbenzene was synthesized and the PAA prepolymer was prepared with 13, 16 and 19 wt % of nickel catalyst. The best percentage of nickel catalyst considered was 13 wt %, due to the
Polímeros. Publicado em: 22/09/2014
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19. SÍNTESE E CARACTERIZAÇÃO DO SISTEMA ESPINÉLIOS CO1-XCUXFE2O4 (X = 1,0, 0,75,0,50, 0,25, 0,0) PELO MÉTODO DOS PRECURSORES POLIMÉRICOS / SYNTHESIS AND CHARACTERIZATION SYSTEM SPINELS CO1-XCUXFE2O4 (X = 1.0, 0,75,0,50, 0.25, 0.0) BY POLYMERIC PRECURSOR METHOD
As ferritas são óxidos compostos, termicamente estáveis, que apresentam estruturas cristalinas equivalentes as do mineral espinélio. Estas retêm propriedades dielétricas, magnéticas e catalíticas específicas. Neste sentido, este trabalho objetiva avaliar a síntese de estruturas espinélios Co1-xCuxFe2O4 (x = 1,0, 0,75, 0,25, 0,0) pelo método do pr
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/09/2012
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20. Ferritas de cobre e zinco do tipo espinélio sintetizadas pelos métodos: hidrotermal assistido por micro-ondas, precursores poliméricos, reação no estado sólido e decomposição térmica / Spinel type copper and zinc ferrites synthesized by the methods: microwave assisted hydrothermal, polymeric precursor, solid state reaction and thermal decomposition.
Ferrites are well studied materials due to their wide application as: gas detector, optical, electronic and magnetic devices, catalyst and pigments. In the synthesis of materials, the properties are extremely influenced by the synthesis method. In this work, four methods were used in the synthesis of spinel ferrites with composition Zn1-xCuxFe2O4 (x = 0,0; 0
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 05/05/2012
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21. Caracterização térmica e estrutural de pós e filmes finos de BaTiO3 sintetizados via método Pechini / Thermal and structural characterization of powders and thin films of BaTiO3 synthesized by Pechini method
Amorphous oxides are chemical compositions whose atomic or molecular configuration does not follow a periodicity like it happens with crystals, which are essentially constituted by oxygen atoms, which has to be the most electronegative element, and other elements. The barium titanate (BaTiO3), amorphous oxide obtained through this work has tetragonal structu
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/02/2012
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22. Influence of the pH on Al2O3:CuO pigments prepared by a polymeric precursor method
Copper (II) aluminate, CuAl2O4, which is known to be an inverse spinel contains a d9 metal ion and possesses interesting electronic, magnetic and catalytic properties and is used in industry as ceramic pigments, coatings and catalysts. Al2O3 with 10 mol% Cu (AlCu10) was synthesized by the polymeric precursor method varying the pH of the precursor solution wi
Mat. Res.. Publicado em: 02/11/2012
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23. Effect of pH-induced nanopowder deagglomeration on sintering, microstructure and dielectric properties of Ba0.77Ca0.23TiO3 ceramics
Ba0.77Ca0.23TiO3 ceramics were produced in this work starting from nanopowders synthesized via a polymeric precursor method. By adjusting the pH values of the precursor solutions above 7, it was possible to prepare powders weakly aggregated and with a smaller particle size, both facts which traduced into an enhanced nanopowders' sintering process at comparat
Materials Research. Publicado em: 17/07/2012
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24. Fabricación y caracterización de espumas de alúmina para aplicación en quemadores porosos radiantes
In radiant porous burners, the heat source requires a solid porous matrix where the combustion reaction takes place, in which the heat transfer is performed more efficiently. This work is based on a study of the alumina suspension rheology, where parameters as viscosity and tixotropy were the guide to select the appropriate formulation for the ceramic foam f
Matéria (Rio J.). Publicado em: 2012