Chemical Synthesis
Mostrando 25-36 de 1413 artigos, teses e dissertações.
-
25. INFLUÊNCIA DA COMPOSIÇÃO DOS NANOFIOS PT-IR/C NA ATIVIDADE CATALÍTICA FRENTE A OXIDAÇÃO ELETROQUÍMICA DE ETANOL EM MEIO ÁCIDO
Carbon-supported platinum-iridium nanowire-shape electrocatalysts containing 20% of metallic loading were synthesized by chemical reduction method using formic acid as a reducing agent and tested towards the oxidation of ethanol in acidic medium. The developed electrocatalysts were synthesized with the following compositions: Pt0.9Ir0.1/C, Pt0.8Ir0.2/C, Pt0.
Quím. Nova. Publicado em: 2020-02
-
26. BIODIESEL SYNTHESIS FROM WASTE COOKING OIL USING A VARIETY OF WASTE MARBLE AS HETEROGENEOUS CATALYSTS
Abstract The research article is based on biodiesel synthesis by the transesterification of waste cooking oil with methanol in the presence of heterogeneous catalysts prepared from different marble. Eight samples of marble were successfully converted into potential catalysts by calcination. The thermal treatment of waste marbles at 300oC-1000oC converted the
Braz. J. Chem. Eng.. Publicado em: 13/01/2020
-
27. In situ DEPOSITION OF COPPER NANOPARTICLES ON POLYETHYLENE TEREPHTHALATE FILTERS AND ANTIBACTERIAL TESTING AGAINST Escherichia coli AND Salmonella enterica
Abstract This study reports a synthesis of copper nanoparticles (CuNP) deposited on polyethylene terephthalate (PET) filters and antibacterial evaluation of the obtained filters against Escherichia coli and Salmonella enterica. CuNP were synthesized by a two-step method involving adsorption of [Cu(OH)4]2- ions onto a PET filter and subsequent chemical reduct
Braz. J. Chem. Eng.. Publicado em: 13/01/2020
-
28. In vitro biological activities of silver nanoparticles synthesized from Scedosporium sp. isolated from soil
One of the important fields in nanotechnology is the development of an environment friendly method for the synthesis of nanoparticles. Many approaches show that microorganisms are the most reliable tools for biosynthesis of nanoparticles compared to physical and chemical methods. In our study, fungi have been exploited for extracellular production of metal n
Braz. J. Pharm. Sci.. Publicado em: 20/12/2019
-
29. Cation Vacancies in NiFe2O4 During Heat Treatments at High Temperatures: Structural, Morphological and Magnetic Characterization
Nickel ferrite (NiFe2O4) was synthesized by mixing stoichiometric amounts of α-Fe2O3 and NiO using mechanical milling and heat treatments at high temperatures. The physical characterization of the samples was carried out using X-ray diffraction, infrared and Raman spectroscopies, Mössbauer spectrometry, magnetization measurements, scanning electron microsc
Mat. Res.. Publicado em: 20/12/2019
-
30. Proteins and Peptides at the Interfaces of Nanostructures
Abstract: The present review focuses on the proteins and peptides at the interfaces of nanostructured metals and semiconductors as a result of their use in synthesis in-situ and functionalization of nanostructures. We start the review with an introduction about the peculiar properties of nanostructured materials and their applications. In the following, the
An. Acad. Bras. Ciênc.. Publicado em: 25/11/2019
-
31. Obtenção de ferritas de cálcio dopadas com cromo visando aplicação em esmaltes transparentes brilhante e mate
RESUMO Este trabalho tem como objetivo obter óxidos com estrutura tipo espinélio de composição CaFe1,8Cr0,2O4 pelo método gelatina, visando aplicação em esmaltes transparentes brilhantes e mate. Os pós precursores, resultantes do processo de síntese, foram calcinados a 600 °C e a 800 °C para a obtenção da fase espinélio. Os pós foram caracteri
Matéria (Rio J.). Publicado em: 25/11/2019
-
32. Síntese de pigmentos de níquel utilizando areia descartada de fundição como fonte de sílica
Resumo Sintetizaram-se pigmentos do sistema Zn2-xNixSiO4 variando a proporção molar de zinco e níquel, partindo da estrutura willemita (Zn2SiO4) à olivina (Ni2SiO4), usando areia descartada de fundição (ADF) e sílica comercial como fontes de SiO2. A ADF foi caracterizada por análise química e DRX. A síntese dos pigmentos seguiu rota cerâmica, com
Cerâmica. Publicado em: 14/11/2019
-
33. Sustainable production of furfural and 5-hidroximetilfurfural from rice husks and soybean peel by using ionic liquid
Abstract In the current search for renewable energy sources, residual biomass has been highlighted as a potential source of chemical compounds that are currently obtained from petroleum. Among the derivatives obtained from this, 5-hydroxymethylfurfural and furfural are considered key parts in this process as they are key compounds in the fine chemical indust
Food Sci. Technol. Publicado em: 28/10/2019
-
34. 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
-
35. Microbial Synthesis and Characterization of Biodegradable Polyester Copolymers from Burkholderia Cepacia and Cupriavidus Necator Strains Using Crude Glycerol as Substrate
Abstract Polymers are materials of pronounced importance in the modern world, since they are massively present in everyday life, especially in the form of packaging. However, most of these materials are derived from non-renewable sources and their disposal generates large volumes of waste, which is extremely damaging to natural environments. In this context,
Braz. arch. biol. technol.. Publicado em: 24/10/2019
-
36. Gold Catalysis for Selective Hydrogenation of Aldehydes and Valorization of Bio-Based Chemical Building Blocks
Gold catalysts are best known for their selectivity in oxidation reactions, however, there is a promising future for gold in selective hydrogenations. Herein, the hydrogenation of several aldehydes and important bio-based chemical building blocks, namely 5-hydroxymethylfurfural (5-HMF), furfural and vanillin, was performed throughout the combination of Au na
J. Braz. Chem. Soc.. Publicado em: 21/10/2019