Organic Matrices
Mostrando 1-12 de 69 artigos, teses e dissertações.
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1. Study of Crystallization and Composition on Silicon Oxycarbide (SiOC) and Silicon Boron Oxycarbide (SiBOC) Ceramics Obtained from Alkoxysilanes Precursors
This work deals on the preparation of silicon oxycarbide (SiOC) and silicon boron oxycarbide (SiBOC) ceramics from pyrolysis involving alkoxysilanes with different organic groups. Boron content, organic substituent and annealing time were evaluated on crystallization and composition of resulting ceramics. B-free precursors composed of methyltriethoxysilane (
J. Braz. Chem. Soc.. Publicado em: 2021-06
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2. BIONANOCOMPÓSITOS POLIMÉRICOS À BASE DE MONTMORILLONITA – MATERIAIS DE INTERESSE CONTÍNUO
Polymeric bionanocomposites are versatile materials that have many practical applications. The wide use of these materials is mainly due to their structure and properties, which combine at nanometric scale, the functionality of biopolymers with the excellent stability of inorganic solids, such as the clay minerals family. Montmorillonite is the most widely e
Quím. Nova. Publicado em: 2020-12
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3. Chemically-Activated Biochar from Ricinus communis L. Cake and Their Potential Applications for the Voltammetric Assessment of Some Relevant Environmental Pollutants
Biochar is a rich-carbon material highly functionalized, which allows the use as electrodes modifier for preconcentration and voltammetric determination of several species. This work describes a castor cake biochar production and chemical activation with different reaction conditions using HNO3 and/or H2O2. Biochar samples were characterized using scanning e
J. Braz. Chem. Soc.. Publicado em: 2020-05
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4. Weathering Resistance of Waterborne Polyurethane Coatings Reinforced with Silica from Rice Husk Ash
Abstract: Waterborne polyurethanes (WPUs) are interesting materials for coatings when compared to solvent-based polyurethanes, once that reducing the concentration of volatile organic compounds that are harmful for human health and the environment. However, the WPU has low weathering resistance. In order to improve this behavior among others properties, ino
An. Acad. Bras. Ciênc.. Publicado em: 25/11/2019
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5. Emerging Contaminants in Trans-American Waters
Resumo O desenvolvimento industrial gerou novos produtos para facilitar a vida das pessoas. Itens como alimentos, higiene, cuidados pessoais e produtos de saúde, entre outros, são processados, vendidos e consumidos diariamente por todas as faixas etárias. Esses produtos incluem em sua formulação produtos químicos orgânicos e inorgânicos com o objetiv
Rev. Ambient. Água. Publicado em: 25/11/2019
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6. Preparation and application of Zero Valent Iron immobilized in Activated Carbon for removal of hexavalent Chromium from synthetic effluent
RESUMO Diferentemente dos contaminantes orgânicos, os metais pesados não são biodegradáveis e tendem a se acumular nos organismos vivos e também são reconhecidos por serem tóxicos ou carcinogênicos. A utilização de nanopartículas de ferro zero valente (nFVZ) é relatada como uma técnica alternativa e de elevado potencial para remediação in situ
Rev. Ambient. Água. Publicado em: 03/10/2019
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7. EFFECT OF Acidithiobacillus thiooxidans-CYSTEINE INTERACTIONS ON PYRITE BIOOXIDATION BY Acidithiobacillus ferrooxidans IN THE PRESENCE OF COAL COMPOUNDS
Abstract This study evaluated the biooxidation of pyrite contained in a Colombian coal (2.38 mm < particle size < 0.50 mm). The variables were cysteine concentration (0-600 mg/L) and culture type (pure Acidithiobacillus ferrooxidans (ATCC 23270) and a consortium of Acidithiobacillus thiooxidans (ATCC 15494) and Acidithiobacillus ferrooxidans). Pyrite oxidati
Braz. J. Chem. Eng.. Publicado em: 30/09/2019
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8. Polydimethylsiloxane as a Matrix for the Stabilization and Immobilization of Zero-Valent Iron Nanoparticles. Applications to Dehalogenation of Environmentally Deleterious Molecules
A wet-synthetic method is described to obtain magnetic, air-stable, zero-valent iron nanoparticles coated with an alkanedioic acid. The particles can be immobilized in an amino-substituted polysiloxane matrix to provide materials capable of dechlorinating, debrominating, and deiodinating a wide variety of halogenated organic molecules dissolved initially in
J. Braz. Chem. Soc.. Publicado em: 2018-07
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9. Coupled monolithic columns as an alternative for the use of viscous ethanol–water mobile phases on chromatographic fingerprinting complex samples
ABSTRACT Concepts of sustainability have received attention from people involved in investigation of nature-derived matrices. The effects of concomitant pollutant activities are cumulative and harmful to the environment from which these matrices are obtained. High performance liquid chromatography analyses generate millions of litters of chemical waste world
Rev. bras. farmacogn.. Publicado em: 2018-06
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10. AVALIAÇÃO DO DESEMPENHO DE UMA FASE SENSORA DE POLIURETANO POR MEIO DA ENERGIA DE GIBBS DE SOLVATAÇÃO E ESPECTROSCOPIA DE INFRAVERMELHO PARA DETERMINAÇÃO DE TOLUENO EM ÁGUA
A novel sensing phase of polyurethane was predicted by quantum chemical calculations as capable of detecting toluene, with the experimental results revealing a limit of detection of 1.4 mg L-1 in the determination of toluene in water samples. The quantum chemical computational strategy was validated by assessing the impact of the polymer matrix sensing phase
Quím. Nova. Publicado em: 2018-04
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11. Strategy for Correction of Matrix Effect on the Determination of Pesticides in Water Bodies Using SPME-GC-FID
This paper investigates a strategy as a quality control parameter, using standard surrogate and determination of a relation factor for determination of parathion-methyl, chlorpyriphos and cypermethrin pesticides in environmental aqueous matrices with distinct characteristics (river water, estuarine, seawater and weir water), using the technique of solid phas
J. Braz. Chem. Soc.. Publicado em: 2017-06
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12. In Tube Ultrasonic and Air Assisted Liquid-Liquid Microextraction-Gas Chromatography-Mass Spectrometry Determination: a Novel Method for the Determination of Phthalate Esters in Aqueous Samples
In this study, a highly sensitive and reliable microextraction method, known as in tube ultrasonic and air assisted liquid-liquid microextraction (IT-UAA-LLME), was developed for the preconcentration of some phthalate esters, such as dimethyl phthalate, diethyl phthalate (DEP), di-butyl-phthalate (DBP), bis(2-ethylhexyl) phthalate (BEHP), butyl benzyl phthal
J. Braz. Chem. Soc.. Publicado em: 2017-06