Excitation Spectra
Mostrando 1-12 de 196 artigos, teses e dissertações.
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1. Spectrofluorimetric Determination of Hydrochlorothiazide by a Carbon Dots-Based Probe via Inner Filtering Effect and Resonance Rayleigh Scattering
Synthesis of carbon dots (CDs) from natural resources not only enables green synthesis and production of environmentally friendly materials, but also provides a cost-effective probe as a fluorescence nanosensor. The proposed sensor introduces a unique one-pot hydrothermal CDs synthesis from alfalfa leaves, which is promising for sensing hydrochlorothiazide (
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Incorporation of Fluorescent Dyes in Electrospun Chitosan/Poly(ethylene oxide)
Polymeric films have been increasingly investigated due to the ease of miniaturization and integration in several sensor devices. Films obtained from the electrospinning technique have a controlled diameter and homogeneity, and substances can be incorporated into the polymeric network. Electrospinning fiber of chitosan (Ch) and poly(ethylene oxide) (PEO) was
J. Braz. Chem. Soc.. Publicado em: 2021-05
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3. Blue Glow Sticks: Cinnamic Acids and Arylacrylonitriles with Liquid-Crystalline Properties and Highly Fluorescent
Five new π-conjugated chromophores derived from acrylic acid and acrylonitrile were synthesized and their thermal and photophysical behaviors were analyzed. They were designed and synthesized through Knoevenagel condensations between arylacetylenebenzaldehydes and a methylene group activated from cyanoacetic and malonic acids. The characterization of the ta
J. Braz. Chem. Soc.. Publicado em: 2021-01
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4. Photoluminescent Investigation of the Doping Site of Eu3+-Doped [Zn3(BTC)2·12H2O] Metal-Organic Framework Prepared by Microwave-Assisted Hydrothermal Synthesis
The [Zn3(BTC)2·12H2O] (BTC = 1,3,5-tricarboxylate) metal-organic framework (MOF) was successfully synthesized using a microwave-assisted hydrothermal synthesis technique, which allowed for significantly decreased reaction time compared to the production of the same compound via conventional heating. In situ doping with Eu3+ ions at concentrations ranging fr
J. Braz. Chem. Soc.. Publicado em: 2020-11
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5. IMPACT OF TEMPERATURE ON THE STABILITY OF SILKWORM COCOON FIBERS
In this study raw and processed silkworm (Bombyx mori) cocoons were investigated using confocal Raman spectroscopy in conjunction with differential scanning calorimetry (DSC) in order to examine the effect of temperature on the molecular conformation of silk fiber structures. Using DSC, a broad endothermic curve was observed at moderate temperatures, sheddin
Quím. Nova. Publicado em: 05/12/2019
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6. H. STAMMREICH AND THE TRIPLE ALLIANCE: THE MOLECULE, THE PROBLEM AND THE INSTRUMENT
Almost 60 years ago H. Stammreich obtained the Raman spectra of two photosensitive molecules, CI4 and SnI4, using a pioneering technology developed by him. At the time the excitation source was homemade gas lamps. The same experiments were repeated by us, with the best technology available, with outstanding correlation, and some new information was obtained
Quím. Nova. Publicado em: 05/12/2019
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7. RAMAN STUDIES OF BIS(PHENYLTERPYRAZINE)IRON(II) AND SUPRAMOLECULAR SPECIES WITH PENTACYANIDOFERRATE(II) IONS
The chemistry and spectroscopy of the iron(II) phenylterpyrazine complex, [Fe(phtpz)2]2+, were investigated in comparison with the analogous phenylterpyridine species, Fe(phtpy)2]2+, and the results indicated a strong electronic delocalization on the Fe(II) terimine chromophore encompassing the lateral pyrazyl groups. The delocalized nature of the molecular
Quím. Nova. Publicado em: 05/12/2019
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8. Interplay between Near-Field Properties and Au Nanorod Cluster Structure: Extending Hot Spots for Surface-Enhanced Raman Scattering
Materials science has observed a continuous increase in the use of metal nanoparticles in a wide range of studies, from fundamental physics to technological applications such as photocatalysis and optical communication devices. This broad scope has the same fundamental origin, the localized surface plasmons, whose excitation leads to strong light confinement
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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9. Hydrothermal Synthesis to Water-stable Luminescent Carbon Dots from Acerola Fruit for Photoluminescent Composites Preparation and its Application as Sensors
Carbon dots (C-dots) possess the attractive properties of high stability, low toxicity, good water solubility, simple synthetic routes as well as size and excitation-dependent photoluminescence (PL).The aim of this work was to synthesize photoluminescent C-dots by hydrothermal method using acerola fruit (Malpighiaemarginata) as a row material, since this fru
Mat. Res.. Publicado em: 06/06/2019
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10. Physiochemical and Optical Properties of GdF3:Pr@LaF3@SiO2 Microspheres
The polyol-based co-precipitation process was employed for synthesis of GdF3:Pr (core) and GdF3:Pr@LaF3 (core-shell) microspheres (MSs). Subsequently, an amorphous silica layer was deposited surrounding the core-shell MSs, which was verified from high-resolution transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX) and FTIR results.
Mat. Res.. Publicado em: 12/04/2018
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11. Effect of Dy3+ Amount on the Structural and Luminescence Properties of LaNbO4:Dy3+ Phosphor Obtained by One-Step Spray Pyrolysis Process
In this study, Dy3+-doped LaNbO4 phosphors with a blue to white emission that can be tuned by varying the activator concentration were prepared by one-step spray pyrolysis process. According to the powder X-ray diffraction results, increasing Dy3+ concentration favored the tetragonal phase. Slight changes were observed in the recorded Raman spectra as a func
J. Braz. Chem. Soc.. Publicado em: 2018-03
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12. Emission Properties Related to Distinct Phases of Sol-Gel Dip-Coating Titanium Dioxide, and Carrier Photo-Excitation in Different Energy Ranges
Titanium dioxide (TiO2) in the form of pellets (pressed powder) and thin films are investigated, revealing the presence of distinct phases: mainly anatase and rutile. Characterization of optical, structural and electrical properties were carried out on samples submitted to different sort of thermal annealing (TA), at distinct temperatures, 500 and 1000ºC, d
Mat. Res.. Publicado em: 20/03/2017