Hydrothermal Synthesis
Mostrando 13-24 de 76 artigos, teses e dissertações.
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13. Synergistic Effect of 4A Zeolite from Rice Husk Ash without Aging Time and Silane on the Adhesion Properties of a Warm Mix Asphalt
4A Zeolite was synthesized using rice husk ash (RHA) as a raw material in a microwave-assisted hydrothermal synthesis. Two new procedures were proposed: procedure A, using RHA as the raw material, and procedure B, using the depolymerized RHA. Both procedures were performed using microwave-assisted hydrothermal synthesis, and neither synthesis required an agi
J. Braz. Chem. Soc.. Publicado em: 2018-01
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14. The Effect of Hydrothermal Treatment on the Morphologies and Optical Properties of Upconversion NaYF 4:Ln 3+ Crystals
This work deals with the synthesis and characterization of upconversion NaYF4:Ln3+ crystals. Co-precipitation and hydrothermal methods were used to synthesize NaYF4:Ln3+ crystals. The experimental procedures were modified to obtain crystals in the cubic (α) phase, hexagonal (β) phase or a mixture between cubic and hexagonal (α/β) phases. Reaction tempera
J. Braz. Chem. Soc.. Publicado em: 2017-09
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15. Influence of Aluminum Addition in the Framework of MCM-41 Mesoporous Molecular Sieve Synthesized by Non-Hydrothermal Method in an Alkali-Free System
Purely siliceous MCM-41 and Al-containing MCM-41 (Al-MCM-41) mesoporous materials were synthesized by non-hydrothermal method in alkali-free ions medium at room temperature and short reaction times. Under these synthesis conditions, it was also investigated the influence of Al incorporation in the crystal structure of MCM-41. The solids were characterized by
Mat. Res.. Publicado em: 17/08/2017
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16. Synthesis of MgAl2O4 by Gelatin Method: Effect of Temperature and Time of Calcination in Crystalline Structure
Magnesium aluminate can be obtained by the methods: ceramic method, sol-gel, co-precipitation, hydrothermal and combustion. However, this work presents a simple and low cost route to obtain MgAl2O4 through the gelatin method. The main objective was to use gelatin as an organic precursor and to verify the influence of temperature and time of calcination on th
Mat. Res.. Publicado em: 06/07/2017
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17. Characterization of ZnAl2O4 Spinel Obtained by Hydrothermal and Microwave Assisted Combustion Method: A Comparative Study
In this work, zinc aluminate spinel was prepared by two methods of directly synthesis (without calcination): microwave assisted combustion and hydrothermal method. The materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and N2-adsorption/desorption isotherms. The XRD patterns confirmed the formation of cubic ZnAl2O4 sp
Mat. Res.. Publicado em: 02/05/2017
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18. Easy and Fast Preparation of TiO2 - based Nanostructures Using Microwave Assisted Hydrothermal Synthesis
TiO2 derivatives with distinct morphologies have been successfully obtained by microwave assisted hydrothermal synthesis in acidic and alkaline medium using mild conditions. Titanium tetraisopropoxide (TTIP) was used as precursor in different environmental conditions under low temperatures, inferior to 150 °C, and short synthesis times, from 2 to 60 min. X
Mat. Res.. Publicado em: 10/04/2017
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19. Synthesis of Surface Oxygen-deficient BiPO4 Nanocubes with Enhanced Visible Light Induced Photocatalytic Activity
The visible light driven BiPO4 nanocubes with sufficient surface oxygen deficiency were fabricated by a hydrothermal process and subsequently ultrasonic assistant Fe reduction process. The products were characterized by XRD, DRS, XPS, SEM and TEM which showed that the BiPO4 had cuboid-like shape with a smooth surface and clear edges and the oxygen vacancies
Mat. Res.. Publicado em: 13/03/2017
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20. Síntese de BaTIO3 e SrTIO3 pelo método hidrotermal assistido por micro-ondas utilizando anatase como precursor de titânio
In this work barium titanate (BT) and strontium titanate (ST) were prepared by Microwave-Assisted Hydrothermal (MAH) method, using a Ti precursor different from those shown in the literature and various concentrations (1, 3 e 6 mol L-1) of KOH mineralizer. As a titanium precursor, an anatase complex with hydrogen peroxide were used. For the precursors of bar
Quím. Nova. Publicado em: 2017-02
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21. TITANATE NANOTUBES PRODUCED FROM MICROWAVE-ASSISTED HYDROTHERMAL SYNTHESIS: CHARACTERIZATION, ADSORPTION AND PHOTOCATALYTIC ACTIVITY
Abstract A microwave-assisted hydrothermal (MAH) method was employed to synthesize TiO2 nanotubes (TNTs) and these were compared to the conventional hydrothermal (CH) method. The nanotubes were characterized for their crystallinity, morphology, surface area and photocatalytic activity. The TiO2 P25 was used for comparison purposes and efficiently degraded bo
Braz. J. Chem. Eng.. Publicado em: 2017-01
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22. Catalytic Capture of CO2 with Template-Containing Zn/MCM-41 and Its Transformation to Solid Carbonate
Mesoporous MCM-41 materials modified by zinc have been prepared by non hydrothermal procedure. Zinc has been introduced by the direct synthesis (DS), template ion-exchange (TIE) and wet impregnation (WI) methods. The catalysts were characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy-scanning electron microscopy (EDX-SEM), thermogra
J. Braz. Chem. Soc.. Publicado em: 2016-12
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23. CdMoO4 Micro-ellipsoids: Controllable Synthesis, Growth Mechanism, and Photocatalytic Activity
CdMoO4 micro-ellipsoids were synthesized by a simple hydrothermal route with the assistance of nonionic surfactant Triton X-100 and characterized by X-ray diffraction, scanning electron microscopy and UV-Vis diffuse reflectance spectroscopy. The effects of hydrothermal pH, temperature, and time on the morphology and photocatalytic activity of CdMoO4 were inv
Mat. Res.. Publicado em: 21/11/2016
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24. Crystallization of Zeolite A Coatings from Natural Zeolite
An investigation was carried out to determine the possibility of preparing coatings of synthetic zeolites on stainless steel from mixtures containing natural zeolite. Hydrothermal synthesis was applied and the coatings obtained were characterized by various techniques. It was observed that crystalline zeolite A coatings could be prepared from natural clinopt
Mat. Res.. Publicado em: 10/11/2016