Metallic Nanoparticles
Mostrando 1-12 de 57 artigos, teses e dissertações.
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1. Analytical method validation for the identification and quantification of dissolved gold and gold nanoparticles in cosmetics products by single particle inductively coupled plasma mass spectrometry
Nanoparticle (NP) applications have recently gained more space in the development of many products, especially in cosmetology. The aim of the present study was to validate a single particle inductively coupled plasma mass spectrometry technique for the detection and quantification of gold nanoparticles (AuNPs) and gold ions (Au (i)) in different cosmetics cu
Quím. Nova. Publicado em: 2021-06
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2. QUANTIFICACAO DE NANOPARTICULAS DE PRATA EM UM PRODUTO FARMACEUTICO POR ESPECTROFOTOMETRIA E POTENCIOMETRIA: UMA PROPOSTA PARA AULAS PRATICAS DE QUIMICA ANALITICA
Spectrophotometry and potentiometry techniques were used to quantify silver in an ophthalmic solution. A standard solution of silver nanoparticles was synthesized, from which an analytical method was developed to quantify silver in the sample. Potentiometric titrations of three samples were made, using an electrochemical cell containing an alternative metall
Quím. Nova. Publicado em: 2021-01
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3. Theoretical Calculations on the Mechanism of Hydrogenation of Diphenylacetylene over Pdn (n = 1-4) Clusters
Diphenylacetylene (DPA) is a precursor of stilbene and benzil, and reduction of DPA or its derivatives with metallic reagents is both an old and contemporary topic of research. By means of density function theory (DFT) calculations, a detailed investigation of the mechanism of the hydrogenation of DPA over Pd clusters was carried out at the molecular level.
J. Braz. Chem. Soc.. Publicado em: 2020-10
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4. Dendritic Gold Nanoparticles Towards Transparent and Electroactive Electrodes
Abstract: The combination of UV-visible absorption and electrochemical experiments (spectroelectrochemistry) enables to obtain highly specific spectroscopic information (in situ and operando) from modified surfaces. However, such application can be limited by the self-absorbance, for example, when metallic nanoparticles are present on modified surfaces. Indi
An. Acad. Bras. Ciênc.. Publicado em: 28/11/2019
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5. Characterization and Cytotoxic Evaluation of Silver and Gold Nanoparticles Produced with Aqueous Extract of Lavandula dentata L. in Relation to K-562 Cell Line
Abstract Metallic nanoparticles have great potential as a chemotherapeutic agent. The aim of this study was to develop and characterize silver and gold nanoparticles using a simple method, as well as evaluating the potential cytotoxic activity in relation to the K-562 cell line. For the synthesis, a solution containing the metallic ions was subjected to mag
Braz. arch. biol. technol.. Publicado em: 25/11/2019
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6. Dielectric Behavior of α-Ag2WO4 and its Huge Dielectric Loss Tangent
The microwave-assisted hydrothermal method was used to obtain α-Ag2WO4. Rietveld refinement confirmed that α-Ag2WO4 is stable in the orthorhombic phase, without secondary phase. However, field-effect scanning electron microscope analysis showed that α-Ag2WO4 nanorods surfaces contain silver nanoparticles, confirmed by the X-ray photoelectron spectroscopy
Mat. Res.. Publicado em: 02/09/2019
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7. STUDY OF THE CHROMIUM(VI) REMOVAL FROM AQUEOUS SYSTEMS BY COBALT NANOPARTICLES
The cobalt nanoparticles (NPs-Co) were synthesized and applied in the removal of Cr(VI). The obtained nanomaterials presented magnetic properties and were characterized by the techniques of Transmission Electron Microscopy and X-ray diffraction. The NPs-Co, with a diameter of less than 50 nm, had a composition based on metallic cobalt and cobalt oxide. The N
Quím. Nova. Publicado em: 18/07/2019
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8. Stress effects on the kinetics of hydride formation and growth in metals
Abstract Although metal hydrides are considered promising candidates for solid-state hydrogen storage, their use for practical applications remains a challenge due to the limitation imposed by the slow kinetics of hydrogen uptake and release, which has driven the interest in using metal nanoparticles as advanced materials of new hydrogen-storage systems sinc
Lat. Am. j. solids struct.. Publicado em: 22/10/2018
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9. Efecto electrocatalítico de nanopartículas bimetálicas de Ag y Cd hacia la reducción de iones nitrato y/o nitrito
ABSTRACT The electrocatalytic effect of Cd-Ag bimetallic nanoparticles supported on highly oriented pyrolytic graphite (HOPG) and vitreous carbon (VC) substrates was evaluated for the nitrate and/or nitrite ions reduction reaction. For this, in a first stage, the metallic and bimetallic deposits were obtained on the carbonaceous substrates (CS) using the ele
Matéria (Rio J.). Publicado em: 19/07/2018
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10. Controlled synthesis of noble metal nanomaterials: motivation, principles, and opportunities in nanocatalysis
ABSTRACT This review describes some principles of the controlled synthesis of metal nanoparticles, focusing on how the fundamental understanding of their synthesis in the solution-phase can be put to tailor size, shape, composition, and architecture. The maneuvering over these parameters not only enable the tuning of properties, but also the maximization and
An. Acad. Bras. Ciênc.. Publicado em: 16/04/2018
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11. Activity and Stability of Dispersed Multi Metallic Pt-based Catalysts for CO Tolerance in Proton Exchange Membrane Fuel Cell Anodes
ABSTRACT Studies aiming at improving the activity and stability of dispersed W and Mo containing Pt catalysts for the CO tolerance in proton exchange membrane fuel cell (PEMFC) anodes are revised for the following catalyst systems: (1) a carbon supported PtMo electrocatalyst submitted to heat treatments; (2) Pt and PtMo nanoparticles deposited on carbon-supp
An. Acad. Bras. Ciênc.. Publicado em: 16/04/2018
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12. Nano-Sized Silver Colloids Produced and Stabilized by Amino-Functionalized Polymers: Polymer Structure-Nanoparticle Features and Polymer Structure-Growth Kinetics Relationships
The synthesis of highly stable silver colloids has been successfully achieved by using reducing/stabilizer amino-functionalized polymers without the aid of any other external agent. The polymer coated inorganic nanoparticles have been detailed characterized via scattering, imaging and UV-Vis spectroscopy. The combination of transmission electron microscopy (
J. Braz. Chem. Soc.. Publicado em: 2017-09