Passivation
Mostrando 1-12 de 52 artigos, teses e dissertações.
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1. Electrochemical Determination of Trifluralin Herbicide Using Silver Solid Amalgam Electrode: Application in Fresh Food Samples
This paper reports the use of polished silver solid amalgam electrode (p-AgSAE) allied to square wave voltammetry (SWV) in the development of a simple, sensitive, fast and green electroanalytical methodology for the trifluralin herbicide determination in fresh food samples. The experimental (supporting electrolyte and potential and time accumulation) and vol
J. Braz. Chem. Soc.. Publicado em: 2021-07
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2. Synthesis of Triazoles by Electro-Assisted Click Reaction Using a Copper Foil Electrode
This paper presents an innovative pathway for the synthesis of triazoles using the well-known “click chemistry” assisted by the electrochemical oxidation of metallic Cu0. The click reaction is used to couple a wide range of biological interest compounds. In this case, faster and less polluting methods for a biological environment was achived by in situ C
J. Braz. Chem. Soc.. Publicado em: 2021-07
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3. NANOCRISTAIS DE PEROVSKITAS COLOIDAIS: HISTÓRICO, PROPRIEDADES E APLICAÇÕES
Recently, a new class of materials, the Perovskite Nanocrystals, also known as perovskite quantum dots (PQDs) has emerged. Perovskite nanocrystals are promising in optoelectronics due to their quantum confinement properties, narrow photoluminescence bands with short decay times, optically tunable bandgaps, easy surface passivation and high photoluminescent q
Quím. Nova. Publicado em: 2020-09
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4. The Comparative Investigation of Corrosion and Passivation for X65 Carbon Steel in pH 1 to 5 HNO3 Solutions without and with 0.01 mol L-1 NaNO2
The influence of 0.01 mol L-1 NaNO2 addition on the corrosion and passivation of X65 carbon steel in pH 1 to 5 HNO3 solutions was investigated and compared by electrochemical methods and microstructural techniques. In the pH 1 to 5 solutions without NaNO2, the X65 steel presented the electrochemical characteristic of active dissolution, and the corrosion rat
J. Braz. Chem. Soc.. Publicado em: 2020-04
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5. Effect of Sigma Phase Precipitated at 850 °C on Corrosion Behaviour of UNS S82441 Duplex Stainless Steel
ABSTRACT Duplex stainless steels (DSS) are alloys with binary microstructure consisting of ferrite (δ) and austenite (γ), combining high mechanical properties and corrosion resistance by pitting and stress corrosion, due to the two phases austenite/ferrite. However, the formation of secondary and intermetallic phases, during solidification processes, heat
Matéria (Rio J.). Publicado em: 16/09/2019
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6. The Effects of pH Values on Functional Mechanisms of Nitrite Anions for Q235 Carbon Steels in 0.01 mol L-1 NaNO2-HCl Solutions
For Q235 carbon steels in 0.01 mol L-1 NaNO2-HCl solutions with different pH values, the effects of pH values on the functional mechanisms of nitrite anions (NO2-) were studied. In the pH 1 and pH 2 solutions, the Q235 steels showed the electrochemical behavior of activation, and uniform corrosion (UC) was the main corrosion type on the Q235 surface. The pre
J. Braz. Chem. Soc.. Publicado em: 12/08/2019
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7. Effect of Sn Addition in the Microstructure Refinement and Corrosion Resistance of Cu-Zr-Al-Ag Alloy
In this paper, a composition of known high glass-forming ability, Cu42Zr42Al8Ag8 and a novel Cu42Zr42Al8Ag4Sn4, were produced by suction-casting. After rapid solidification of both alloys, X-ray diffraction patterns along with crystallite size estimation by Scherrer equation and scanning electron microscopy images revealed a refined microstructure, composed
Mat. Res.. Publicado em: 04/04/2019
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8. Lignin-First Biorefining of Lignocellulose: the Impact of Process Severity on the Uniformity of Lignin Oil Composition
In lignin-first biorefining via reductive processes, lignocellulosic materials are deconstructed by the solvent extraction of lignin in the presence of a hydrogenation catalyst. This approach provides a route to the successful extraction and reductive passivation of lignin fragments to produce low molar mass lignin oils together with high-quality pulps. Here
J. Braz. Chem. Soc.. Publicado em: 2019-03
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9. METODOLOGIA PARA DETECÇÃO ELETROQUÍMICA QUALITATIVA DE COMPOSTOS ORGÂNICOS EM INTERFACES PETRÓLEO/ÁGUA
The possibility of detecting some organic compounds directly in a petroleum/water interface was described. Aqueous phase was composed by 1 x 10-3 mol L-1 NaCl solution and the oil phase was carried out using crude oil forming an oil/water interface. Carbon based screen-printed electrodes was used in conjunction with square-wave voltammetry technique, constit
Quím. Nova. Publicado em: 2019-01
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10. Study of the Corrosive Behavior of the AISI 1020 Steel in Acid Crude Oil by Microscopic Techniques (LM, AFM and SEM/EDX) and Raman Spectroscopy
Microscopic techniques were combined to study the influence of corrosion rate on the morphologic behavior of AISI 1020 steel specimens submitted to thermal degradation of a typical acid crude oil (total acid number (TAN) = 2.1390 mg KOH g-1 and total sulfur (S) = 0.7778 wt.%). The techniques used were light microscopy (LM), scanning electron microscopy/energ
J. Braz. Chem. Soc.. Publicado em: 2018-08
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11. Characterization of CBD-CdS Doped with Some Rare Earths III (Eu3+,Ce3+) as Function of Synthesis Time
Rare earths (Europium, cerium)-doped CdS nanofilms are prepared using the growth technique chemical bath deposition (CBD) at the reservoir temperature of 70±2°C varying the synthesis time in a wide range. For the rare earths doped CdS nanofilms the synthesis time was ranged from 80 to 135 min. The rare earths molar concentration was in the range 0.0≤x≤
Mat. Res.. Publicado em: 01/02/2018
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12. Heat Treatment Effects on ASTM A890/A 890M GR 5A Super Duplex Stainless Steel Passivity
Heat treatment can modify the corrosion resistance of stainless steels. Thus, the corrosion behavior of ASTM A890/A 890M GR 5A super duplex stainless steels (SDSS) has been investigated in aqueous 60,000 ppm NaCl solution by several electrochemical tests. The specimens were aged for 2, 10, 50 and 100 hours at 475 ºC. Potentiodynamic polarization studies sho
Mat. Res.. Publicado em: 22/01/2018