Acid Activation
Mostrando 1-12 de 4366 artigos, teses e dissertações.
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1. Nicotine as a Catalyst for Chlorination Promoted by Hypochlorous Acid: Experimental and Theoretical Studies
There is robust evidence of the hypochlorous acid (HClO)-mediated damage in biomolecules, and nicotine boosts the chlorination potency of HClO. We present experimental and theoretical evidence of the mechanism by which nicotine catalyzes the chlorination of pyranine. The rate constants for chlorination of pyranine by HClO were measured in the presence (5.3 �
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. Purification of raw palygorskite: a comparative study involving different processes and dispersing agents
Abstract Palygorskite (Pal) is a natural clay mineral with fibrous morphology and high surface area. Depending on the geological origin, it presents impurities, such as quartz and carbonates, which can harm some of its properties. Therefore, this work seeks to define a viable methodology for the purification of a Brazilian Pal. Two types of mixing processes
Cerâmica. Publicado em: 2021-06
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3. Compatibility by a Nonisothermal Kinetic Study of Azathioprine Associated with Usual Excipients in the Product Quality Review Process
Azathioprine is an immunosuppressive drug for several inflammatory disorders. Due to its clinical relevance, to explore the solid-state properties for excipient compatibility in the product quality review process is essential. Fourier transform infrared spectroscopy, powder X-ray diffraction and thermal analysis (thermogravimetry/derivative thermogravimetry
J. Braz. Chem. Soc.. Publicado em: 2021-03
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4. Aqueous Extract of Cumaru (Dipteryx odorata) Seeds as Corrosion Inhibitor for Mild Steel in Hydrochloric Acid Solution
The corrosion inhibition of mild steel by aqueous extract of cumaru (Dipteryx odorata) seeds and its high molecular weight fraction (HMWF) was investigated in 1 mol L-1 HCl solution. The study was carried out through gravimetric essays, open circuit potential measurements, anodic and cathodic polarization curves and electrochemical impedance analyses, as wel
J. Braz. Chem. Soc.. Publicado em: 2021-02
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5. Brazilian Mineral Clays: Classification, Acid Activation and Application as Catalysts for Methyl Esterification Reactions
In this study, three raw Brazilian clays from João Pessoa, Paraíba State (Aço AP, AVL and Verde Lodo) were characterized before and after purification and acid activation. Several instrumental techniques were used, and the raw clays were classified as dioctahedral smectites with different compositions, where the AVL sample had the highest content of montm
J. Braz. Chem. Soc.. Publicado em: 2021-01
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6. An Efficient and Recyclable Sn-Based Phosphotungstic Acid with Tunable Brønsted/Lewis Acidity for Selective Oxidation of Benzyl Alcohol
A series of metal ion (M = Sn2+, Fe3+, Ni2+, Co2+, Ag+, Cu2+) exchanged tungstophosphoric acid (H3PW12O40; TPA) catalysts with tunable Brønsted/Lewis acidity were synthesized and exploited for the oxidation of benzyl alcohol (BzOH) to benzaldehyde (BzH) using hydrogen peroxide (H2O2) as oxidant. The structure of these M-TPA composite salts was also characte
J. Braz. Chem. Soc.. Publicado em: 2021-01
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7. Exogenous gibberellin and cytokinin in a novel system for in vitro germination and development of African iris (Dietes bicolor)
ABSTRACT The availability of reliable and reproducible micropropagation systems is a decisive step to successfully propagate plant species with slow growth and low germination rate. The effect was investigated of gibberellin (GA) and cytokinin (CK) in the in vitro germination and development of Dietes bicolor (Steud.) Sweet ex Klatt. Seeds were inoculated in
Rev. Ceres. Publicado em: 2020-10
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8. Mechanistic Investigation of DBU-Based Ionic Liquids for Aza-Michael Reaction: Mass Spectrometry and DFT Studies of Catalyst Role
1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU)-based ionic liquids (ILs) has exhibited a high catalytic activity in the aza-Michael reactions compared to conventional catalysts and with imidazole-based ILs. In the present work DBU-based ILs showed high catalytic potential for aza-Michael addition of aromatic amines to 2-cyclohexen-1-one under solvent-free conditio
J. Braz. Chem. Soc.. Publicado em: 2020-09
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9. Escala de Depressão, Ansiedade e Estresse: propriedades psicométricas e prevalência das afetividades
In this study we have expanded upon a family of substituted pentacyclic oxadiazadiborinane derivatives from the condensation of carbohydrazide with ortho-formylphenyl boronic acid derivatives containing a variety of chemical and physical properties. All new complexes have been characterized fully including two single crystal X-ray diffraction studies which c
J. bras. psiquiatr.. Publicado em: 2020-07
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10. Challenges in Pharmacological Management of Cardiovascular Diseases in Covid-19: do Benefits Outweigh Risks?
In this study we have expanded upon a family of substituted pentacyclic oxadiazadiborinane derivatives from the condensation of carbohydrazide with ortho-formylphenyl boronic acid derivatives containing a variety of chemical and physical properties. All new complexes have been characterized fully including two single crystal X-ray diffraction studies which c
Int. J. Cardiovasc. Sci.. Publicado em: 2020-07
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11. Synthesis, Characterization and Antimicrobial Activities of Pentacyclic Oxadiazadiborinanes
In this study we have expanded upon a family of substituted pentacyclic oxadiazadiborinane derivatives from the condensation of carbohydrazide with ortho-formylphenyl boronic acid derivatives containing a variety of chemical and physical properties. All new complexes have been characterized fully including two single crystal X-ray diffraction studies which c
J. Braz. Chem. Soc.. Publicado em: 2020-07
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12. 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