Scanning Electron Transmission
Mostrando 13-24 de 637 artigos, teses e dissertações.
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13. Chitosan-Sodium Alginate Polyelectrolyte Complex Coating Pluronic® F127 Nanoparticles Loaded with Citronella Essential Oil
Pluronic® F127 nanoparticles were loaded with citronella essential oil (CEO) and then covered with chitosan-sodium alginate polyelectrolyte complex (PEC). The system was characterized according to size, zeta potential and stability over time. Dynamic light scattering (DLS) in different proportions of water/ethanol as a dispersive medium was important in con
J. Braz. Chem. Soc.. Publicado em: 2020-04
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14. Synthesis, Characterization and Photocatalytic Activity of Au/SiO2@TiO2 Core-Shell Microspheres
By using HAuCl4 as the gold precursor, spherical Au@SiO2/TiO2 core-shell nanostructures were prepared with the sol-gel method and ethanol reflux. The preparation process was convenient and fast. The obtained samples were characterized by UV-Vis, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TE
J. Braz. Chem. Soc.. Publicado em: 2020-03
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15. Morphological characterization of pollen grains of Brazilian species of Bombacoideae (Malvaceae s.l.)
ABSTRACT The pollen grains of 15 species belonging to five genera (Ceiba Mill., Eriotheca Schott & Endl., Pachira Aubl., Pseudobombax Dugand, and Rhodognaphalopsis A. Robyns) of the subfamily Bombacoideae (Malvaceae s.l.) were acetolysed, measured, described and photomicrographed under light microscopy and scanning and transmission electron microscopy, in or
Acta Bot. Bras.. Publicado em: 2020-03
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16. Revisiting hydropotes of Nymphaeaceae: ultrastructural features associated with glandular functions
ABSTRACT Hydropotes are specialized epidermal structures involved in water and mineral flux into and out of the plant body. We analyzed hydropote morphology of four species of Nymphaeaceae: Nymphaea caerulea, Nymphaea lotus, Nymphaea rubra, and Victoria amazonica. Leaf samples were processed following conventional techniques for plant anatomy and for scannin
Acta Bot. Bras.. Publicado em: 2020-03
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17. Screening of the Au:Pt Atomic Ratio Supported in SrCO3: Effects on the Performance of the Solvent-Free Oxidation of Benzyl Alcohol
We have prepared, by a sol-immobilization method, bimetallic catalysts with different Au:Pt atomic ratios supported on commercial SrCO3. The catalytic performance for the oxidation reaction of benzyl alcohol of such materials was compared to the monometallic counterparts, aiming at the obtaining of the best composition of the material. It was found that the
J. Braz. Chem. Soc.. Publicado em: 2020-03
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18. Experimental and Theoretical Study of LiMn2O4 Synthesized by the Solution Combustion Method Using Corn Starch as Fuel
Lithium manganese oxide, LiMn2O4, was synthesized in two temperature stages, where the first consisted by an ecofriendly solution combustion method at 300 °C. Finally, the as-burned powders were thermal treated at 500 and 700 °C. The structural and morphological changes were evaluated by the Rietveld method and density functional theory (DFT) calculations.
J. Braz. Chem. Soc.. Publicado em: 2020-02
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19. GRAPHENE OXIDE AND A GO/ZnO NANOCOMPOSITE AS CATALYSTS FOR EPOXY RING-OPENING OF EPOXIDIZED SOYBEAN FATTY ACIDS METHYL ESTERS
Abstract In this work, the grapheme oxide (GO) and GO/ZnO nanocomposite were successfully obtained from the oxidation of graphite and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). In the GO/ZnO nanocomposite, the GO sheets were coated with aggregated
Braz. J. Chem. Eng.. Publicado em: 09/12/2019
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20. Hydrogen production from aqueous glycerol using titanate nanotubes decorated with Au nanoparticles as photocatalysts
Abstract: Protonated titanate nanotubes (HTiNts) were synthesized using the hydrothermal method, followed by proton exchange with acid. Gold nanoparticles decorated titanate nanotubes (AuHTiNts) were obtained by the reduction of AuCl4- under vigorous stirring with an aqueous solution of HTiNts containing 1 wt% of ascorbic acid. To investigate the surface str
An. Acad. Bras. Ciênc.. Publicado em: 28/11/2019
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21. Revisiting hydropotes of Nymphaeaceae: ultrastructural features associated with glandular functions
ABSTRACT Hydropotes are specialized epidermal structures involved in water and mineral flux into and out of the plant body. We analyzed hydropote morphology of four species of Nymphaeaceae: Nymphaea caerulea, Nymphaea lotus, Nymphaea rubra, and Victoria amazonica. Leaf samples were processed following conventional techniques for plant anatomy and for scannin
Acta Bot. Bras.. Publicado em: 11/11/2019
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22. Bionanocomposites of PLA/PBAT/organophilic clay: preparation and characterization
Abstract The objective of this study was to develop bionanocomposites from blends of poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) and from 3% and 6% bentonite clay. Initially, the bentonite clay was treated with Praepagen salt, and the properties of the modified clay were evaluated. After the organophilization of the clay was co
Polímeros. Publicado em: 04/11/2019
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23. Green synthesis and Characterization of ZnO-CoFe2O4 Semiconductor Photocatalysts Prepared Using Rambutan (Nephelium lappaceum L.) Peel Extract
In this work, the semiconductor of ZnO-CoFe2O4 composites were prepared by green synthesis approach using rambutan peel extract (Nephelium lappaceum L.) as a capping agent. X-ray diffraction patterns of composites showed the main peaks of ZnO at 2θ = 31.8°, 34.5°, and 36.2° corresponding to hexagonal wurtzite structure and weak peak at 2θ = 35.4° for c
Mat. Res.. Publicado em: 30/09/2019
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24. Estudio de las propiedades, estructurales, morfológicas y ópticas de nanopartículas de Cr2O3 sintetizadas por procesos de combustión de un solo paso y diferentes combustibles
ABSTRACT This research presents a novel one–step solution combustion synthesis to obtain nano-structured Cr2O3 from chrome nitrate solution and one fuel such as aspartic acid (Asp) or Lysine (Lys), or Autor Restrihydroxymethylaminomethane (Tris) or ethylenediaminetetraacetic acid (Edta). Once obtained, the ashes were calcined at 500°C. The powders were ch
Matéria (Rio J.). Publicado em: 16/09/2019