Complexing
Mostrando 1-12 de 231 artigos, teses e dissertações.
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1. DEVELOPMENT AND OPTIMIZATION OF A SPECTROPHOTOMETRIC METHOD WITH CLOUD POINT EXTRACTION FOR DETERMINATION OF GADOLINIUM
This work describes a simple, sensible, and low-cost analytical method, based on cloud-point extraction (CPE) of the surfactant (1,1,3,3-Tetramethylbutyl)phenyl-polyethylene glycol (Triton X-114), for the efficient extraction and sensible determination of gadolinium after its complexation with 1-(2-pyridylazo)-2-naphthol (PAN) and subsequent determination by
Química Nova. Publicado em: 2022
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2. Elemental Chalcogen (Se, S) in PEG-400 to the Synthesis of Seleno- and Thioflavones from 2-Chlorophenyl Ethynyl Ketone and Nucleophilic Species of Chalcogen
An alternative green method was developed for the synthesis of thio-and selenoflavones by the ring closure of 2-chlorophenyl ethynyl ketone with NaHY (Y = S, Se). These nucleophilic chalcogen species were generated in situ using NaBH4 to reduce the elemental chalcogen in the presence of polyethylene glycol-400 (PEG-400). The efficiency of this reaction is st
J. Braz. Chem. Soc.. Publicado em: 2021-08
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3. Interaction of Pb, Ni and Cd with Aquatic Humic Substances of Amazonian Blackwater Rivers
In this study, the extraction and characterization of aquatic humic substances (AHS) from two blackwater rivers in the Amazon basin was carried out in order to assess the seasonal effects in the AHS structure. In addition, an investigation of the complexing capacities (CC) of the structures containing the metal ions CdII, NiII and PbII was also done. The cha
J. Braz. Chem. Soc.. Publicado em: 2021-02
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4. Separation of gadolinium and europium from chloride media by the solvent extraction technique
Abstract Obtaining rare earth elements (REE) is a complicated task, due mainly to the difficulty of separating and purifying them. Solvent extraction is the most widely used technique for separating REE, and the most common extractants used are organophosphorus acids. The low selectivity of this technique leads to the need for a high number of extraction cel
REM, Int. Eng. J.. Publicado em: 2020-03
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5. SELECTIVE SEPARATION OF Mn(II) AND Cd(II) AS WELL AS REGENERATION OF POLYMER VIA SHEAR INDUCED DISSOCIATION COUPLING WITH ULTRAFILTRATION
Abstract The selective separation of Mn(II) and Cd(II) as well as regeneration of the complexing agent were conducted by shear induced dissociation coupling with ultrafiltration (SID-UF), and the copolymer of maleic acid and acrylic acid (PMA) was used as complexing agent. At the optimal complexation conditions, pH 6 and P/M (mass ratio of polymer to metal i
Braz. J. Chem. Eng.. Publicado em: 13/01/2020
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6. Controlled Dehydration of Fe(OH)3 to Fe2O3: Developing Mesopores with Complexing Iron Species for the Adsorption of β-Lactam Antibiotics
In this work, efficient adsorbents for β-lactam antibiotics based on mesoporous iron oxide containing surface [FeOx(OH)y] sites were produced by controlled precipitation of iron hydroxide and thermal treatment at 150, 200, 300 and 450 ºC (150FeOH, 200FeOH, 300FeOH and 450FeOH, respectively). Mössbauer, X-ray diffraction (XRD), thermogravimetry-mass spectr
J. Braz. Chem. Soc.. Publicado em: 2019-02
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7. Complexation and enhancement of temozolomide solubility with cyclodextrins
ABSTRACT Temozolomide is a poorly soluble anti-cancer drug used in the treatment of some brain cancers. Following literature reports about the enhancement of solubility and stability for these kinds of drugs upon complexation with cyclodextrins, we aimed to form an inclusion complex between temozolomide and the different types of cyclodextrins (CDs) to enhan
Braz. J. Pharm. Sci.. Publicado em: 26/07/2018
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8. Green Processing of Strategic Elements Based on Magnetic Nanohydrometallurgy
Magnetic nanohydrometallurgy (NHM) is a new process based on engineered superparamagnetic nanoparticles capable of performing as complexing agents for extracting and recovering strategic metals from mineral sources and urban wastes, as well as for removing hazardous elements from contaminated water. Its principles and application are reviewed in this paper.
J. Braz. Chem. Soc.. Publicado em: 2018-05
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9. PROCESSING OF SPENT ZINC-MnO2 DRY CELLS IN VARIOUS ACIDIC MEDIA
This paper describes a route for recovering manganese and zinc from spent zinc-MnO2 dry cells via acid leaching. Sulfuric, hydrofluoric and formic acids were used as leachants. Hydrogen peroxide was added as reductant, except for formic acid since it is itself a reductant. Experiments were run at 25-40 ºC for 1-3 h. Under the best optimal conditions, over 9
Quím. Nova. Publicado em: 2018-02
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10. Electroremediation of deactivated catalysts from fluidised catalytic cracking for vanadium removal - the effect of a dual cathode chamber reactor
Abstract The aim of this study was to evaluate the quantity of vanadium removed through electrokinetic remediation applied to catalyst waste used in a fluid catalytic cracking process. In excess, vanadium affects process efficiency by reducing the catalyst’s activity, causing deactivation and reducing its useful life in petroleum cracking during refining.
Braz. J. Chem. Eng.. Publicado em: 2018-01
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11. Effectiveness acidic pre-cleaning for copper-gold ore
Abstract The presence of copper-bearing minerals is known to bring on many challenges during the cyanidation of gold ore, like high consumption of cyanide and low extraction of metal, which are undesirable impacts on the auriferous recovery in the subsequent process step. The high copper solubility in cyanide prevents the direct use of classical hydrometallu
REM, Int. Eng. J.. Publicado em: 2017-12
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12. Synthesis and Characterization of LiCoO2 from Different Precursors by Sol-Gel Method
Lithium cobalt oxide, LiCoO2, widely used as cathode in lithium ion batteries was synthesized and their structural and electronic properties investigated. The crystalline powders were prepared by the sol-gel method with four complexing agents: citric acid, glycine, starch and gelatin. These syntheses were compared with the blank test (without complexing agen
J. Braz. Chem. Soc.. Publicado em: 2017-11