Ionic Exchange
Mostrando 1-12 de 191 artigos, teses e dissertações.
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1. Preparation and performance of magnetic zirconium-iron oxide nanoparticles loaded on palygorskite in the adsorption of phosphate from water
Magnetic zirconium-iron oxide nanoparticles loaded on palygorskite as a low-cost adsorbent was produced by one-step co precipitation technique and its properties for phosphate adsorption were overall investigated. The Brunauer Emmett Teller (BET) specific surface area analysis, scanning electron microscopy (SEM), thermo gravimetric analysis (TGA), Fourier tr
Química Nova. Publicado em: 2022
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2. Structural Study of Phenolic Acids by Triple Quadrupole Mass Spectrometry with Electrospray Ionization in Negative Mode and H/D Isotopic Exchange
This work reports the theoretical and experimental study of fragmentation reactions in the gas phase of five phenolic acids using triple quadrupole mass spectrometry by electrospray ionization in negative ionic mode, as well as the isotope exchange experiments. MS/MS spectra were analyzed to suggest the fragmentation mechanisms, while theoretical calculation
J. Braz. Chem. Soc.. Publicado em: 2020-02
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3. Modeling boron adsorption on five soils before and after removal of organic matter
ABSTRACT Boron- B concentrations that cause deficiency and those that cause toxicity appear to be very similar, compared to other nutrients, which can complicate successful management of this element in soils. In this study, B adsorption onto two Oxisols from Brazil (Rhodic Eutroperox and Anionic Acroperox), two Alfisols (Natric Palexeralf and Aridic Paleust
Sci. agric. (Piracicaba, Braz.). Publicado em: 04/11/2019
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4. New Strategies in Enantioselective Hydrogenation on Supported Transition Metal Catalyst: Effects of Metal Sintering and Support Swelling
The effect of noble metal catalysts supported on an ionic exchange resin for the enantioselective hydrogenation of ethyl pyruvate to ethyl lactate was studied. High activity and moderate enantioselectivity levels were obtained. Pt was the best enantioselective metallic phase, followed by Pd and Au; Rh was the less enantioselective metallic phase. The effect
J. Braz. Chem. Soc.. Publicado em: 12/08/2019
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5. Produtividade de Pinus caribaea VAR. hondurensis e suas relações com atributos químicos dos solos em região de Cerrado brasileiro
Resumo A silvicultura com espécies exóticas desempenha importante papel socioeconômico no Brasil, fornecendo matéria-prima para a produção de madeira, lenha, carvão vegetal, celulose, dentre outros. Nesse sentido, torna-se necessário o aprofundamento do conhecimento sobre as variáveis ambientais que controlam a produtividade do Pinus; em especial, a
Ciênc. Florest.. Publicado em: 30/05/2019
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6. Evaluation of Biopolimeric Films of Cassava Starch with Incorporation of Clay Modified by Ionic Exchange and its Application as a Coating in a Fruit
Coatings technologies with biopolymeric films are effective in maintaining the chemical and sensory characteristics of several fruits. Cassava starch is an attractive biopolymeric because of its renewable characteristics and low cost, but it has a high transfer rate of water vapor. Hydrophilic compounds of organically modified montmorillonite clay by ion exc
Mat. Res.. Publicado em: 22/01/2018
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7. Cellulose Oxidation and the Use of Carboxyl Cellulose Metal Complexes in Heterogeneous Catalytic Systems to Promote Suzuki-Miyaura Coupling and C-O Bond Formation Reaction
This work shows the modification of microcrystalline cellulose by the selective oxidation of primary hydroxyl groups to carboxylate groups by a 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated system and its application as a heterogeneous ligand by ionic exchange with catalytic metals ions such as palladium, nickel and copper. Afterwards is desc
J. Braz. Chem. Soc.. Publicado em: 2017-11
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8. Ion Exchange Chromatography and Mass Bias Correction for Accurate and Precise Zn Isotope Ratio Measurements in Environmental Reference Materials by MC-ICP-MS
Precise and accurate d66/64Zn data for environmental reference materials (RMs) including rocks, sediments, soils and plants are presented in order to improve the metrological traceability and analytical control of Zn isotope ratio determinations in future environmental studies. Previously developed ion exchange chromatography protocols were adjusted to enabl
J. Braz. Chem. Soc.. Publicado em: 2017-02
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9. Preparation and Characterization of an Eco-Friendly Polymer Electrolyte Membrane (PEM) Based in a Blend of Sulphonated Poly(Vinyl Alcohol)/ Chitosan Mechanically Stabilised by Nylon 6,6
Abstract Membranes for fuel cell applications were prepared using two polymer blends: poly(vinyl alcohol) (PVAL) and chitosan (CS), 80/20 (w/w) and 60/40 (w/w) with and without nylon. Sulfosuccinic acid (SSA) was used both as a crosslinking and a sulfonating agent. An increasing in the SSA content raised ionic exchange capacity and consequently proton conduc
Mat. Res.. Publicado em: 21/07/2016
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10. MOLECULAR VALIDATED MODEL FOR ADSORPTION OF PROTONATED DYE ON LDH
Abstract Hydrotalcite-like compounds are anionic clays of scientific and technological interest for their use as ion exchange materials, catalysts and modified electrodes. Surface phenomenon are important for all these applications. Although conventional analytical methods have enabled progress in understanding the behavior of anionic clays in solution, an e
Braz. J. Chem. Eng.. Publicado em: 2016-03
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11. Mineral content of ionomer cements and preventive effect of these cements against white spot lesions around restorations
This study evaluated the ion exchange at the material/enamel interface and the preventive effect of restorative materials submitted to cariogenic challenge against white spot. Restorations in enamel/dentin of bovine teeth were performed with composite resin (Filtek™ Z250 – control group) and glass-ionomers cements - GICs (Ionomaster R™ and Fuji IX™ -
Braz. oral res.. Publicado em: 29/08/2014
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12. Cloning and characterization of newly isolated lipase from Enterobacter sp. Bn12
A mesophilic Enterobacter sp. Bn12 producing an alkaline thermostable lipase was isolated from soil in Tehran, Iran. The lipase gene (ELBn12) was identified from a genomic library. Sequence analysis of the DNA fragment revealed an open reading frame of 879 bp encoding a lipase with a molecular mass of 31.3 kDa. The deduced amino acid sequence showed 96% iden
Braz. J. Microbiol.. Publicado em: 2014-06