Infrared Light
Mostrando 1-12 de 286 artigos, teses e dissertações.
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1. Carbon Dots from Pilosocereus gounellei for Fluorimetric Determination of Tannin in Tea Using a Flow-Batch System
In this study, xiquexique (Pilosocereus gounellei) native endemic cactus from the Brazilian semiarid was used for the first time as a natural carbon source (“green precursor”) for the synthesis of highly fluorescent carbon dots (CDs). These CDs were successfully used to develop a fast, low-cost, eco-friendly fluorescence method for the determination of t
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. Household Infrared Technology as an Energy-Efficient Approach to Achieve C-Cπ Bond Construction Reactions
We examined the ability of short-wave infrared (IR) light in the λ1.5-3.0 μm region of the infrared emission spectrum to accomplish C-Cπ bond construction reaction between π-excessive azaheteroaromatic and different carbonyl substrates supported on a bentonitic clay catalyst in solventless condition via a three-component condensation reaction. Preliminar
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Enhancement of Visible Light-Responsive Photocatalytic Efficiency by Using a Laccaic Acid-Modified Titanium Dioxide Photocatalyst
In this study, a laccaic acid-modified TiO2 photocatalyst (Lac-TiO2) was prepared via an impregnation method with 0.50, 1.00, 2.50, and 5.00 wt.% laccaic acid. The products’ physical properties were examined through X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), X-ray photoemission spectroscopy (XPS), UV-Vis diffused
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. Characterization of Commercially Available Turmeric for Use in Pharmaceutical Products and Food Supplements
We addressed some physicochemical and biological differences in commercial turmeric, acquired from both handling pharmacies and stores selling natural products for quality assessment. For this, it was determined the melting point, antioxidant activity by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), antimicrobial activity via the agar disk-diffusion assay,
Journal of the Brazilian Chemical Society. Publicado em: 2022
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5. Dextran Sulfate/Pramlintide Polyelectrolyte Nanoparticles as a Promising Delivery System: Optimization, Evaluation of Supramolecular Interactions and Effect on Conformational Stability of the Peptide Drug
In this study, we investigated the feasibility to obtain nanoparticles (NPs) by assembling pramlintide (Pram) with dextran sulfate (DexS), as a new approach for mucosal peptide delivery. DexS/Pram NPs were prepared by dropwise addition of a Pram solution to a DexS solution under magnetic stirring. The physicochemical characteristics of NPs and molecular inte
J. Braz. Chem. Soc.. Publicado em: 2021-08
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6. Agro-Industrial Waste Valorization: Transformation of Starch from Mango Kernel into Biocompatible, Thermoresponsive and High Swelling Nanogels
Mango industry processing disposes 40-60% of this fruit as residues, such as peels and kernels. The exploration of bioproducts from these industrial rejects can reduce environmental impact besides of producing high value-added materials. In this scenario, carboxymethyl starch nanoparticles were produced from mango (Mangifera indica L.) kernel starch. These n
J. Braz. Chem. Soc.. Publicado em: 2021-08
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7. Wavelength-Selective Near Unity Absorber Based on Fabry-Pérot Nanoresonators
Abstract We proposed and analyzed a planar narrow-band absorber based on a bi-layer metal/dielectric structure. The planar absorber uses the Fabry-Pérot resonance and the inherent loss of the metals, for maximum light absorption in the range of the electromagnetic spectrum visible to the near infrared. The absorption resonance peak can be shifted to other r
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-06
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8. Structural Study of Wheat Gliadin in Different Solvents by Spectroscopic Techniques
Physicochemical properties of gliadin in different solvents (dimethyl sulfoxide (DMSO), H2O, and aqueous ethanol) and pH (9.8, 6.8, and 1.2) were investigated using dynamic light scattering (DLS), zeta potential (ZP), and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Gliadin-DMSO and gliadin-deionized water (H2O) (pH 9.8) s
J. Braz. Chem. Soc.. Publicado em: 2021-04
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9. Improving Photoluminescence Quantum Yield of CdTe Quantum Dots Using a Binary Solvent (Water + Glycerin) in the One-Pot Approach Synthesis
The present work describes the comparison of the optical and structural properties between CdTe quantum dots (QD) synthesized in water and in the binary solvent (water + glycerin) via one-pot approach synthesis. The optical properties of the nanocrystals obtained with different synthesis parameters were characterized by UV-visible and photoluminescence spect
J. Braz. Chem. Soc.. Publicado em: 2021-04
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10. 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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11. A Calix[4]arene-Functionalized Perylene Imide and Its Luminescence Properties
In this study, new perylene-derived molecules were synthesized as perylene-3,4,9,10-tetracarboxylic acid monoanhydride monopotassium carboxylate 1; N-(3-propanol)perylene-3,4,9,10-tetracarboxylic-3,4-(monoimide)anhydride-9,10-acid potassium carboxylate 2; 5,11,17,23-tetra(tert-butyl)-25,27-bis(3’-bromopropoxy)-26,28-(dihydroxy)calix[4]arene 3; 5,11,17,23-t
J. Braz. Chem. Soc.. Publicado em: 2020-11
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12. Calcium oxalate content from two Amazonian amilaceous roots and the functional properties of their isolated starches
Abstract The calcium oxalate content from two Amazonian amilaceous roots, Xanthosoma sagittifolium and Pachyrhizus tuberosus, before and after cooking were studied in the present work. Calcium oxalate raphides were observed by light microscopy in longitudinal sections from fresh tubers. The functional properties and physicochemical characteristics of isolate
Food Sci. Technol. Publicado em: 2020-09