scholarly journals Application of the Sol-Gel Method at the Fabrication of PLZT:Yb3+ Ceramics

2016 ◽  
Vol 61 (3) ◽  
pp. 1441-1446 ◽  
Author(s):  
K. Osińska ◽  
M. Płońska ◽  
A. Marzec
Keyword(s):  
Thermal Evolution ◽  
Physical Adsorption ◽  
Sol Gel ◽  
Chemical Properties ◽  
Chemical Characterization ◽  
Simultaneous Thermal Analysis ◽  
Ceramic Materials ◽  
Gel Method ◽  
Sol Gel Method ◽  
Before And After

Abstract The aim of presented study was to obtain the PLZT:Yb3+ ceramics. Nanopowders of itterbium doped PLZT materials were synthesized by the sol-gel method from high quality metaloorganic precursors, as lead (II) acetate, lanthanum acetate, ytterbium acetate, zirconium (IV) propoxide and titanium (IV) propoxide. Anhydrous acetic acid and n-propyl alcohol were used as solvents, while acetyloacetone was added as stabilizer of hydrolysis reactions. Thermal evolution of the dried gels, before and after calcination, was studied by the simultaneous thermal analysis. The amorphous PLZT:Yb3+ gels were first calcined in the furnace at T = 850°C, and then mixed in the planetary ball mill. Additionally, the mean particle sizes were calculated by means of powder specific surface area measurements, based on the BET physical adsorption isotherm. Such obtained powders were subsequently pressed into pellets, and sintered by the free sintering method at temperature T = 1250°C / 6h. The morphology of fabricated PLZT:Yb3+ ceramic powders and samples was studied using Scanning Electron Microscopy. Chemical characterization of samples was carried on using the Energy-dispersive X-ray spectroscopy - EDS system. Studies provided detailed data concerning the relationships between doping and preparing conditions on the basic physical and chemical properties of obtained ceramic materials.

Structuring-agent role in physical and chemical properties of Mo/SiO2 catalysts by sol-gel method

2018 ◽  
Vol 89 (2) ◽  
pp. 416-425
Author(s):  
William Giovanni Cortés-Ortiz ◽  
Alexander Baena-Novoa ◽  
Carlos Alberto Guerrero-Fajardo
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Gel Method ◽  
Sol Gel Method ◽  
Physical And Chemical ◽  
And Chemical Properties

scholarly journals Preparation and Photocatalytic Performance of ZnO/Sepiolite Composite Materials

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Chao Li ◽  
Huijuan Li ◽  
Guicheng He ◽  
Zhiwu Lei ◽  
Wenyuan Wu
Keyword(s):  
Composite Materials ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
Environmental Pollutants ◽  
Chemical Properties ◽  
Treatment Method ◽  
Blue Dye ◽  
Synthesis Methods ◽  
Gel Method ◽  
Sol Gel Method

Photocatalytic technology is a widely used water treatment method, whose efficiency can be increased by developing a suitable photocatalyst fabrication procedure. In this study, five different synthesis methods were utilised for the preparation of novel ZnO/sepiolite photolytic composites, namely, sol-gel method, hydrothermal reduction, hydrolytic precipitation, powder sintering, and impregnation-reduction. The obtained photocatalysts were characterised by scanning electron microscopy, infrared spectroscopy, and X-ray diffraction. The differences between the applied photocatalyst preparation methods and the reasons for these differences were discussed, and the photocatalytic activities of the prepared composite materials were compared. The obtained results revealed that the physical structure, chemical properties, and photocatalytic performance of the composite produced by the sol-gel method were superior to those of the materials fabricated by the other four methods. Moreover, this material also exhibited high photocatalytic stability, while its photocatalytic degradation of methylene blue dye proceeded via a quasi-first-order reaction. The prepared composites have broad application prospects in photocatalysis and can be potentially used for treating environmental pollutants.

Structural, Textural and Thermal Characterization of Nano-Mg/Al Hydrotalcite before and after Cr (VI) Removal

2013 ◽  
Vol 755 ◽  
pp. 53-60
Author(s):  
Esthela Ramos Ramírez ◽  
Norma Leticia Gutiérrez Ortega ◽  
Cesar Augusto Contreras Soto ◽  
Gustavo Rangel Porras
Keyword(s):  
Crystalline Structure ◽  
Sol Gel ◽  
Textural Properties ◽  
Kinetic Studies ◽  
Thermal Characterization ◽  
Gel Method ◽  
Sol Gel Method ◽  
Before And After ◽  
Short Time

In this work there was studied the structural, textural and effect that has treat thermal on the removal of Cr (VI) of nanoMg/Al hydrotalcite (NHT) synthesized by the sol-gel method with a ratio of Mg/Al=3. These present the characterization of the nanoMg/Al hydrotalcite before and after Cr (VI) removal, as well as the kinetic studies and of balance. In agreement with the results, when the NHT are thermal treated to 350 °C the hydrotalcite crystalline structure remains but the textural properties are improved and structural. The NHT synthesized by the sol-gel method present a good capacity of removal with values of 91 mg of Cr (VI) removed / g of NHT. The above mentioned capacity of removal gets improved after thermal treating the material, reaching values of removal of 124 mg of Cr (VI) removed / g of NHT. The NHT with the Cr (VI) absorbed show decrease of the crystalline structure, as well as a saturation of the pores that annuls the porosity due to the fact that the Cr (VI) lodges both at the pores and at the intersheets. The time that him takes the HLM to remove the Cr (VI) of the watery solution is alone of 2 minutes, with which it is possible to conclude that the NHT have an excellent aptitude to remove Cr (VI) of watery solutions in an interval of very short time.

Preparation of Sulfated Zirconia Using Modified Sol Gel Method

2014 ◽  
Vol 896 ◽  
pp. 153-158
Author(s):  
Anis Kristiani ◽  
Kiky C. Sembiring ◽  
Fauzan Aulia ◽  
Joddy Arya Laksmono ◽  
Silvester Tursiloadi ◽  
...  
Keyword(s):  
Sulfated Zirconia ◽  
Sol Gel ◽  
Chemical Properties ◽  
Gel Method ◽  
Sol Gel Method ◽  
Organic Bases ◽  
Physico Chemical ◽  
Medium Porosity ◽  
Cetyltrimethyl Ammonium ◽  
Physical And Chemical

A series of sulfated zirconia was prepared through sol gel method in alcohol medium. Porosity of the catalyst was developed in two different methods, which were immersion of cetyltrimethyl ammonium chloride (CTAC) surfactant as templating agent and Supercritical Fluid Extraction (SFE). The physico-chemical properties of the catalysts were characterized by Thermal Gravimetric-Differential Thermal Analysis (TG-DTA), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET) and Barret-Joyner-Halenda (BJH) and gravimetry method for acidity measurement following by the adsorption of organic bases. The characterization results show that different method of immersing CTAC surfactant and SFE affecting physical and chemical properties, i.e. crystalinity, surface area, pore size, pore volume and acidity.

scholarly journals Ceramic Materials. Preparation and Properties of ZrO2-Coated BaTiO3 Composite Particles by Sol-Gel Method with Zr-Alkoxide.

2001 ◽  
Vol 50 (6) ◽  
pp. 630-633 ◽  
Author(s):  
Takashi HAYASHI ◽  
Akihiro TANIMURA ◽  
Hiroshi SHINOZAKI ◽  
Kazuya TAKANASHI ◽  
Hideyuki AOKI ◽  
...  
Keyword(s):  
Sol Gel ◽  
Ceramic Materials ◽  
Composite Particles ◽  
Gel Method ◽  
Sol Gel Method ◽  
Materials Preparation

Synthesis and Characterization of CaO-SiO2-MgO Bioactive Glass Produced by Sol-Gel

2016 ◽  
Vol 720 ◽  
pp. 252-256
Author(s):  
Nadia Mohammed Elmassalami Ayad ◽  
Andre Ben Hur da Silva Figueiredo ◽  
Wilma de Araujo Gonzalez ◽  
Daniel Navarro da Rocha ◽  
Rubens Lincoln Santana Blazutti Marçal ◽  
...  
Keyword(s):  
Fumed Silica ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Gel Method ◽  
Sol Gel Method ◽  
Before And After ◽  
Ft Ir ◽  
Silica Precursor ◽  
Gelling Time

Bioactive glasses have widely used in biomedical applications such as bone filler due to their excellent biocompatibility, bioactivity and osteoconduction characteristics. In this work, a silicate-rich glass was synthesized by the sol-gel method with 60% SiO2 – 30%CaO – 10% MgO composition where fumed silica acts as the silica precursor. This new method was hypothesized to reduce the gel formation time, due to the high surface area of the fumed silica. In addition, this would presumably increase the nanoporosity of the glass. For comparison purposes, we used a glass of the same composition, but with the conventional silica precursor, tetraethyl orthosilicate (TEOS), through the sol gel method. Both were heat treated at 450°C. FT-IR analysis before and after heat treatment at 450°C showed the presence of nitrate groups, especially in the TEOS samples. This is consistent with the more hygroscopic aspect of those samples. The fumed silica samples had significantly less pronounced peaks corresponding to the nitrate groups, consistent with the more porous structure and the less hygroscopic aspect. The fumed silica samples indeed had a lower gelling time and showed similar results obtained by XRD and FT-IR analyses, showing that the use of fumed silica is viable and advantageous in the glass synthesis by the sol-gel process

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