Crystalline
Mostrando 1-12 de 1638 artigos, teses e dissertações.
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1. Tailoring the properties of Y2O3 via synthesis parameters varied during the PVA-assisted sol-gel route
Abstract The effect of synthesis parameters on the microstructural behavior and morphology during the yttrium oxide (Y2O3) formation is reported. Y2O3 crystals were produced by a modified sol-gel route assisted by polyvinyl alcohol solution varying the calcination temperature and solution pH. The crystalline phase formation was investigated using X-ray powde
Cerâmica. Publicado em: 2023
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2. Simultaneous Quantification of Amorphous and Crystalline Valsartan in Tablets Using Raman Spectroscopy and Chemometrics Tools
Valsartan is an antihypertensive active pharmaceutical ingredient (API), it is used in the amorphous state in the commercial products. As amorphous materials are metastable, amorphous valsartan can crystallize to valsartan E, promoting changes in the dissolution and bioavailability of the drug. Tablets containing metastable forms of APIs need special conditi
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Production of nanostructured crystalline composite using residual ashes from flocculated sludge burning process in a poultry slaughterhouse wastewater treatment system
Abstract Nanostructured crystalline composite (activated carbon) was synthesized from residual ashes of the burning process of the sludge generated in the flotation step of a poultry slaughterhouse and was used for Allura red dye adsorption. The ashes were chemically activated using two types of reagents, H2O2 and H3PO4, and the structure, morphology, and su
Cerâmica. Publicado em: 2022
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4. A New Synthetic Route and Comprehensive Topological Study of a Benzimidazole Derivative
Benzimidazole and its derivatives are molecules that have diverse biological properties, therefore we synthesized and studied a new benzimidazole to understand their physical/chemical properties. The compound was obtained through a new synthetic route, using graphite oxide, in the absence of solvent, with crystalline packaging supported by C-H…N and C-H…
Journal of the Brazilian Chemical Society. Publicado em: 2022
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5. Mullite macro-needles for reinforcement of refractory castables
Abstract Ceramic macro-needles incorporation as reinforcement in commercial refractory castable was studied. Ceramic macro-needles (Ø2x20 mm) were made from kaolinite clay and gibbsite to obtain mullite as the main crystalline phase. Specimens with the ceramic reinforcement were evaluated by compression after being treated at two temperatures (815 and 1400
Cerâmica. Publicado em: 2022
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6. Effect of sintering temperature on mechanical and bioactivity properties of bioactive glass and cordierite composite
Abstract In this study, a composite of bioactive glass (BG) and cordierite (BG-cord) was proposed to increase the strength and bioactivity of BG. Both BG and cordierite were separately synthesized with the method of glass melting, then, they were used to fabricate BG-cord with a variation of sintering temperature (600 to 1000 °C). The highest diametral tens
Cerâmica. Publicado em: 2022
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7. Phase transformation of kaolinite to hexagonal kalsilite using K2CO3
Abstract Hydrothermal synthesis of kalsilite was facilitated by the inclusion of potassium carbonate (K2CO3) as the source of the potassium ion. After a 24 h reaction at 220 °C, kaolin clay treated with 1.25 M K2CO3 showed the most significant peaks at 2θ of 28.5° and 34.7° by X-ray diffraction corresponding to the hexagonal kalsilite. In addition, field
Cerâmica. Publicado em: 2022
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8. Microstructural characteristics, properties, synthesis and applications of mullite: a review
Abstract Mullite, an intermediate phase of the binary alumina-silica system, is one of the most important phases of ceramic products containing alumina and silica in the initial composition. Its stoichiometry ranges from 3Al2O3.2SiO2 (3:2) to 2Al2O3.SiO2 (2:1) and its crystalline structure is orthorhombic, characterized by the presence of octahedral chains o
Cerâmica. Publicado em: 2022
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9. Boosting the Photocurrent of the WO3/BiVO4 Heterojunction by Photoelectrodeposition of the Oxy-Hydroxide-Phosphates Based on Co, Fe, or Ni
Here we investigated the photoelectrodeposition of oxygen-evolving catalysts (OECs) based on oxy-hydroxides-phosphates of Co, Fe, or Ni (CoPi, FePi, and NiPi) on the WO3/BiVO4 heterojunction and their activity in water oxidation. The OECs were deposited by cycles of (i) open-circuit potential (OCP) and (ii) applying a potential positive enough to oxidize the
Journal of the Brazilian Chemical Society. Publicado em: 2022
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10. Biphasic 0.8BaTiO3/0.2Ni(1-x)CoxFe2O4 nanopowders by in situ sol-gel synthesis
Abstract Nanopowders of the 0.8BaTiO3/0.2Ni(1-x)CoxFe2O4 (x=0, 0.25, 0.5, 0.75, and 1) were synthesized by the in situ sol-gel method using poly(acrylic acid) (PAA1800) as a chelating agent. The synthesis developed using PAA1800 ensured the simultaneous crystallization of two phases. The results provided a reliable method for producing biphasic nanopowders i
Cerâmica. Publicado em: 2022
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11. Analysis and evaluation of structural properties of Co3O4 microparticles obtained at low temperature
Abstract In the present research, the synthesis of cobalt oxide Co3O4 was carried out using the sol-gel technique with subsequent heat treatment at 225 and 235 °C. The final product obtained was characterized by X-ray diffraction (XRD), showing a pure crystalline phase of Co3O4, cell parameters a=b=c=8.071 Å, and a volume of 525.7 Å3. The particle size wa
Cerâmica. Publicado em: 2022
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12. Simple and fast process using hydrochloric acid for producing synthetic zinc-rich stevensite
Abstract In the last decades, clays have been used in sectors such as health and cosmetics. This requires products that are increasingly pure and present homogeneous properties, hardly found in natural clays. The use of synthetic clays can be a solution. For this, it is necessary to explore techniques for their production. The main focus of this study was to
Cerâmica. Publicado em: 2022