Sol Gel Transition
Mostrando 1-12 de 21 artigos, teses e dissertações.
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1. Adsorption of Calcium(II), Cadmium(II) and Copper(II) Ions from Water by Prepared Silicon-Aluminum-Zirconium Oxide Using Sol-Gel Process
Ternary oxide silica-alumina-zirconia (SiO2/Al2O3/ZrO2) obtained by the sol-gel process was applied as novel adsorbent of ions in aqueous solution. Batch isotherms were performed using standard CuII, CdII and CaII solutions at variable pH and different concentrations. Adsorption capacity was best at weakly acidic pH. The maximum adsorption capacities were 2.
J. Braz. Chem. Soc.. Publicado em: 2021-07
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2. F-127-Assisted Sol-Gel Synthesis of Gd2O3:Eu3+ Powders and Films
In the current work, the influence of Pluronic F-127 (S = F-127) and temperature on the luminescent properties of Gd2O3:Eu3+ (Gd:S = 1:2) powders and films was studied. In order to synthesize the powders and films (by the dip-coating technique), Gd2O3: Eu3+ (5 mol%) ceramics were elaborated by the sol-gel route, using gadolinium and europium nitrates as prec
Mat. Res.. Publicado em: 08/04/2019
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3. Effect of hydroxyurea (HU) on gelatinization mechanism of type I collagen suspensions
ABSTRACT Mutant hemoglobins thermodynamic phase transitions (HbS, HbC, etc.) have been the causes of serious hemoglobinopathies that have been affecting mankind since the dawn of human race. HbS polymerization is the best known of these transitions and the original cause of sickle cell anemia. Hydroxyurea (HU, NH2CONHOH) is widely used as the main drug admin
Matéria (Rio J.). Publicado em: 06/12/2018
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4. Synthesis and characterization of lithiated nanostructures
ABSTRACT Regardless of the simple accumulation of ions in the crystal insertion sites, nanomaterials offer a new storage mechanism of lithium ions (Li+), these storage mechanisms are formed in the interfaces and inside of the nanopores. Such kinds of storage mechanisms have no effect on the structure of the electrode material. Consequently, the charge-discha
Matéria (Rio J.). Publicado em: 19/07/2018
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5. 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
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6. Formulation and characterization of poloxamer 407®: thermoreversible gel containing polymeric microparticles and hyaluronic acid
The influence of the composition and preparation method on the sol-gel transition temperature (Tsol-gel) and rheological response of poloxamer-based formulations was determined. Manual and more complex mechanical stirring were found to provide similar results. In addition, a linear dependence of Tsol-gel on the poloxamer content was observed in the range of
Quím. Nova. Publicado em: 2013
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7. Influence of the hydrolysis and condensation time on the preparation of hybrid materials
This work describes the hydrolytic sol-gel synthesis of silica particles prepared by a modified Stöber route, using the organofunctionalized alkoxide 3-methacryloxypropyl trimethoxysilane and tetraethylorthosilicate. The silica particles were obtained through basic catalysis from a mixture of precursor alkoxides, water, and isopropyl alcohol. Samples were p
Materials Research. Publicado em: 04/02/2011
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8. Preservation of rhizobia by Iyophilization with trehalose.
The objective of this study was to determine if trehalose can effectively enhance the viability and storage lifetime of Rhizobium tropici and Rhizobium etli after lyophilization as compared to the traditional protective combination of sucrose and peptone. Two strains of bean-nodulating rhizobia were effectively preserved in the lyophilized state by 100 mM tr
Pesquisa Agropecuária Brasileira. Publicado em: 2011
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9. Evaluation of bulk and surfaces absorption edge energy of sol-gel-dip-coating SnO2 thin films
The absorption edge and the bandgap transition of sol-gel-dip-coating SnO2 thin films, deposited on quartz substrates, are evaluated from optical absorption data and temperature dependent photoconductivity spectra. Structural properties of these films help the interpretation of bandgap transition nature, since the obtained nanosized dimensions of crystallite
Materials Research. Publicado em: 2010-12
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10. PRODUÇÃO E CARACTERIZAÇÃO DE ALUMINOSILCATOS LUMINESCENTES PARA APLICAÇÕES INDUSTRIAIS / PRODUCTION AND CHARACTERIZATION OF ALUMINOSILCATOS LUMINESCENT FOR INDUSTRIAL APPLICATIONS
This work aimed the synthesis and characterization of pure and doped calcium aluminosilicates using the proteic sol-gel method and by a new route, which combines the proteic sol-gel method with the solid state synthesis. In the proteic sol-gel method, coconut water (Cocos nucifera) is used as a starting solvent. But for the aluminosilicates synthesis, one of
Publicado em: 2010
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11. Transição sol-gel em soluções orgânico-aquosas de lisozima e o efeito indutor do solvente: caracterização cinética e estrutural / Sol-gel transition in aqueous-organic solutions of lysozyme and the solvent-inducing effect: a kinetic and structural characterization
Lysozyme sol-gel transition in tetramethylurea/water was investigated in depth. These dispersions produced highly viscous systems, which evolved to physical gels, i.e., systems where the gel backbone is maintained by van der Walls forces and hydrogen bonding. The work was conducted in two fronts: a) the study of lysozyme dispersions in binary mixtures; b) th
Publicado em: 2006
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12. "Electrochromic devices with solid polymeric electrolytes based on starch" / "Dispositivos eletrocrômicos com eletrólitos sólidos poliméricos à base de amido"
This dissertation presents the results of preparation and characterization of five electrochromic devices (DEC) composed of thin films of transition metal oxides, such as WO3, WO3:Ta, Nb2O5:Mo and NiOx as electrochromic layers and CeO2-TiO2 as a transparent counter-electrode. The electrolytes used in these devices were starch-based plasticized with glycerol
Publicado em: 2006