Solid State Reaction
Mostrando 1-12 de 142 artigos, teses e dissertações.
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1. Analysis of dielectric and electrical transport properties of NdFeAsO ceramic
Abstract The iron-based ceramic NdFeAsO was synthesized by the solid-state reaction method. The tetragonal crystal structure was confirmed at room temperature through the X-ray diffraction technique. The dielectric characteristics i.e. dielectric constant (εr) and loss tangent (tanδ) of the sample were studied at a wide range of temperature and frequencies
Cerâmica. Publicado em: 2022
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2. New Greener Method for the Preparation of Heteropolyacid Compounds (HPW) Modified with Metallic Tin and Application in the Lactic Acid Esterification Reaction
The main objective of this work was to design an innovative method to prepare heterogeneous heteropolyacid catalysts. The heteropolyacid H3PW12O40 (HPW) was modified with tin(II) by two methodologies: a conventional aqueous ion-exchange (CS) and a redox solid-state (SS). In both cases, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD
J. Braz. Chem. Soc.. Publicado em: 2021-03
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3. An Efficient and Recyclable Sn-Based Phosphotungstic Acid with Tunable Brønsted/Lewis Acidity for Selective Oxidation of Benzyl Alcohol
A series of metal ion (M = Sn2+, Fe3+, Ni2+, Co2+, Ag+, Cu2+) exchanged tungstophosphoric acid (H3PW12O40; TPA) catalysts with tunable Brønsted/Lewis acidity were synthesized and exploited for the oxidation of benzyl alcohol (BzOH) to benzaldehyde (BzH) using hydrogen peroxide (H2O2) as oxidant. The structure of these M-TPA composite salts was also characte
J. Braz. Chem. Soc.. Publicado em: 2021-01
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4. ANODES FOR SOFC: REVIEW OF MATERIAL SELECTION, INTERFACE AND ELECTROCHEMICAL PHENOMENA
This paper presents a comprehensive interface and electrochemical phenomena review of different anodes for SOFC. In this way, it was possible to select some mixed electronic and ionic conductor materials alternatives to the conventional anode, Ni-YSZ conductor. New materials must present a satisfactory electronic and ionic conductivity at intermediate temper
Quím. Nova. Publicado em: 2021-01
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5. Evaluation of the Influence of the Substituting Cation on the Structural and Morphological Properties of the New Garnet Sm3−xREExFe5O12 (REE = Dy, Gd and Lu)
Rare earth garnets (REE3Fe5O12) have magnetic-electric and optical properties that can be used in transmitters, microwave and data storage devices. These properties depend mainly on partial or total substitution of the cationic sites, as well as by the synthesis method used. Therefore, in this work was studied the influence of the substituting cation on the
Mat. Res.. Publicado em: 20/01/2020
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6. Modification of Chitosan by Zincke Reaction: Synthesis of a Novel Polycationic Chitosan-Pyridinium Derivative
Chitosan is a biodegradable aminopolysaccharide produced by deacetylation of acetamide groups of chitin, one of the most abundant organic materials in nature. Many different types of organic reactions have been described to modify the functional groups of chitosan and produce materials with applications in a large number of areas. However, the Zincke reactio
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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7. KINETIC STUDIES OF HYDROLYSIS REACTION OF NaBH4 WITH γ-Al2O3 NANOPARTICLES AS CATALYST PROMOTER AND CoCl2 AS CATALYST
Abstract Solid-state hydrogen storage is of considerable concern as a potential hydrogen source for portable fuel cell applications. This study mainly focuses on kinetics of NaBH4/Al2O3 nanoparticles (20 nm)/H2O system with CoCl2 as catalyst and the factors that affect the hydrogen generation rate (HGR). It is observed that the reaction rate increases consid
Braz. J. Chem. Eng.. Publicado em: 30/09/2019
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8. Citotoxicidade in vitro de nanopartículas de fosfato tricálcico-β sintetizado via reação em estado sólido
RESUMO O Fosfato Tricálcico-β (TCP-β) é um material sintético que apresenta composição química similar à do tecido ósseo, sendo, por essa razão, frequentemente empregado como biomaterial. Nesta pesquisa, TCP-β foi sintetizado por reação via estado sólido e caracterizado por Difração de Raios X (DRX), Espectroscopia de Infravermelho (IV), Mic
Matéria (Rio J.). Publicado em: 13/06/2019
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9. Síntese, caracterização e modificação da hidroxiapatita com zinco para aplicação na reação de esterificação
RESUMO A hidroxiapatita tem se destacado entre os materiais cerâmicos devido a sua versatilidade estrutural, pois permite a substituição do Ca2+ ou do PO43-da sua estrutura possibilitando diversas aplicações. A utilização da hidroxiapatita como suporte e, ou catalisador tem recebido destaque como tema de pesquisa. Com isso, o objetivo deste trabalho f
Matéria (Rio J.). Publicado em: 20/05/2019
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10. Citotoxicidade in vitro de nanopartículas de fosfato tricálcico-β sintetizado via reação em estado sólido
RESUMO O Fosfato Tricálcico-β (TCP-β) é um material sintético que apresenta composição química similar à do tecido ósseo, sendo, por essa razão, frequentemente empregado como biomaterial. Nesta pesquisa, TCP-β foi sintetizado por reação via estado sólido e caracterizado por Difração de Raios X (DRX), Espectroscopia de Infravermelho (IV), Mic
Matéria (Rio J.). Publicado em: 20/05/2019
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11. Transport Properties of Polycrystalline Mixed Copper-Zinc Ferrites
Polycrystalline mixed Cu-Zn spinel ferrites with general formula Cu1-xZnxFe2O4 (x = 0.0, 0.1, 0.3, 0.5 and 0.7) have been prepared by solid-state reaction method. The effect of Zn2+ ions on transport properties such as DC and AC resistivity, dielectric constant and dielectric loss tangent has been presented in this paper. The resistivity increases with Zn co
Mat. Res.. Publicado em: 19/04/2018
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12. GLASSPANACEA: UM SOFTWARE EFICIENTE PARA A FORMULAÇÃO DE MATERIAIS CERÂMICOS
GlassPanacea is an efficient software tool that combines several attractive technical features with ease of use. Its configuration leads to the intuitive handling and learning with accurate results, providing the users with flexibility in the selection of suitable chemicals for the formulation of glassy, partially glassy or crystalline ceramic materials, as
Quím. Nova. Publicado em: 2018-04