Solvents
Mostrando 1-12 de 1233 artigos, teses e dissertações.
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1. Qual o sistema adesivo deve ser utilizado durante a técnica de dentina úmida?
Durante a utilização da técnica de adesão à dentina úmida os sistemas adesivos mais recomendados são os que contêm em sua composição os solventes álcool ou acetona
. A razão do melhor desempenho desse tipo de solvente em dentina úmida é que, após a desmineralização e exposição das fibras de colágeno, estas se mantêm expandidas
Núcleo de Telessaúde Sergipe. Publicado em: 12/06/2023
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2. Recent Developments on Palladium-Catalyzed Carbonylation Reactions in Renewable Solvents
Palladium-catalyzed carbonylation reaction has surfaced as a robust tool for insertion of the carbonyl group into organic molecules, and in the last decades enormous progress has been made. Nowadays, a plethora of methodologies is available to synthesize all kinds of carbonyl compounds. However, the focus has shifted during recent years to address rising con
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Supercritical Carbon Dioxide Effect on Lipase-Catalyzed Geranyl Acetate Synthesis
This work provides a general insight on lipase-catalyzed synthesis of geranyl acetate through esterification of geraniol with acetic acid. Although this reaction is relatively well known, the replacement of organic solvents by supercritical fluids is fairly recent and the role of CO2 is still not completely understood. Therefore, reactions were performed wit
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. METHODS FOR EXTRACTION AND ISOLATION OF AGATHISFLAVONE FROM POINCIANELLA PYRAMIDALIS
Agathisflavone is a natural biflavone with restricted occurrence in plants. This biflavone presents several biological activities and can be important to developing new drugs. Obtaining such a molecule on a large scale for in vivo tests is a challenge. To date, there are no reports regarding its synthesis; thus, it is important to improve and develop methods
Química Nova. Publicado em: 2022
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5. OBTENÇÃO DE AMINAS PRIMÁRIAS A PARTIR DA REDUÇÃO DE NITROCOMPOSTOS AROMÁTICOS VIA PROTOCOLOS DE REAÇÕES SUSTENTÁVEIS EM MEIO AQUOSO
Aromatic amines are important intermediates in the industry to produce a wide array of products, and the reduction of aromatic nitro compounds is the main methodology for their preparation. Considering this fact, the objective of this review is to describe the development of sustainable methodologies for the reduction of aromatic nitro compounds for their re
Química Nova. Publicado em: 2022
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6. An Eco-Friendly Proposal by Integrating Chromatographic Fingerprinting and Multivariate Control Chart in a Non-Target Analysis to Evaluate Grape Juices from Different Farming Practices
A potential eco-friendly method without organic solvents is presented by integrating a chromatographic fingerprint and multivariate control chart based on Q residuals to differentiate grape juices from different farming practices. The sample preparation was only water dilution, and the mobile phase was water acidified with sulfuric acid, which can be readily
Journal of the Brazilian Chemical Society. Publicado em: 2022
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7. A Green Analytical Method Using Polyurethane Foam for The Extraction and Determination of Lauryl Ether Sulfate in Personal Care Hygiene Products
A green methodology was developed for the extraction and determination of lauryl ether sulfate in raw materials and commercial liquid soap and shower gel samples. The method avoids the use of organic solvents, offering a simple, cheap, and safe analysis. The methodology is based on the sorption of an ionic pair consisting of a cationic dye and an anionic sur
Journal of the Brazilian Chemical Society. Publicado em: 2022
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8. Sustainable and Reusable Sulfonic Acid-Functionalized Task-Specific Ionic Liquid Catalysts for Multicomponent Reactions. A Review
Improvements in Sustainable Organic Synthesis are usually related to the investigation of less hazardous, non-corrosive and renewable materials, as well as waste prevention, energy efficiency, solvent-free reactions, and the development of efficient reusable catalysts. In this context, multicomponent reactions emerged as important strategies for the rapid an
Journal of the Brazilian Chemical Society. Publicado em: 2022
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9. What is new in non-chromatographic flavonoid purification?
Flavonoids are metabolites occurring in all plant tissues and present different biological activities. They occur in a mixture of similar polarity with laborious separation and purification processes, usually furnishing low yields. Semi-preparative chromatographic methods are universally employed procedures for their isolation. This paper discusses the state
Química Nova. Publicado em: 2022
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10. EFFECT OF REACTION CONDITIONS ON PARTICLE SIZE OF ZNO NANOPARTICLES VIA CONTROLLED PRECIPITATION METHOD AND IN-VITRO ANTIBACTERIAL CAPACITY
High-yield ZnO spheroidal nanoparticles with an average diameter around 23 nm (≈ 25% frequency) and 30 nm (≈ 28% frequency) were obtained by controlled semicontinuous precipitation at low temperatures. This synthesis was obtained from hydrozincite (Zn5(CO3)2(OH)6) as primary nanoparticles. The Zn5(CO3)2(OH)6 nanoparticles were synthesized by hydrolysis o
Química Nova. Publicado em: 2022
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11. Solventes eutéticos naturais profundos (NADES) no preparo de amostras de rocha fosfática e suplemento mineral para determinação elementar por técnicas de plasma
Natural deep eutectic solvents (NADES) based on xylitol, citric acid, and malic acid were synthesized and used in ultrasound-assisted extraction (UAE) and heating-bath extraction of phosphate rock and mineral supplement samples. Arsenic, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, P and Zn were determined by inductively coupled plasma mass spectrometry (ICP-MS) and i
Quím. Nova. Publicado em: 2021-06
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12. A Greener Enzymatic Oligoesterification of Biobased Renewable Synthons
Polyesters of xylitol and succinic acid were prepared yielding from 70 to 75% by enzyme-catalyzed esterification using a molar mass from 1:1 to 2:5 at 120 and 140 °C employing from 1 to 10% m/m of enzyme. Control over branching degree was achieved by tuning the reaction conditions (temperature, time, comonomer ratio, enzyme content). This one-step process f
J. Braz. Chem. Soc.. Publicado em: 2021-06