scholarly journals Influence of the Microwaves on the Sol-Gel Syntheses and on the Properties of the Resulting Oxide Nanostructures

2020 ◽  
Author(s):  
Luminita Predoana ◽  
Dániel Attila Karajz ◽  
Vincent Otieno Odhiambo ◽  
Irina Stanciu ◽  
Imre M. Szilágyi ◽  
...  
Keyword(s):  
Sol Gel ◽  
Oxide Nanoparticles ◽  
Processing Temperature ◽  
Microwave Assisted ◽  
Oxide Nanostructures ◽  
Gel Technique ◽  
Gel Preparation ◽  
Sol Gel Synthesis ◽  
And Control ◽  
Preparation Techniques

Among the chemical methods in the liquid phase, the sol–gel technique is a versatile and efficient method for pure or doped metal oxide films or powders preparation, showing some advantages over other preparation techniques (high homogeneity, the possibility to introducing dopants in large amount, low processing temperature and control over the stoichiometry). Combining the sol–gel (SG)method with the effect of ultrasounds(US) or microwaves (MW) leads to improving the sol–gel procedure. The microwave-assisted sol–gel method is most frequently used for obtaining nanocrystalline, monodispersed oxide nanoparticles, or to transform amorphous gels into well-crystallized nanopowders. Less studied is the influence of the microwaves on the sol–gel reactions in solutions. The benefit of using microwave-assisted sol–gel preparation highly depends on the reagents used and on the composition of the studied systems. In the present chapter, results on the influence of the microwaves on the chemical reactions that take place during the sol–gel synthesis and on the properties of the resulted samples are discussed.

Novel Glass-Ceramics for Dental Application by Sol Gel Technique

2008 ◽  
Vol 396-398 ◽  
pp. 153-156 ◽  
Author(s):  
Xanthippi Chatzistavrou ◽  
E. Hatzistavrou ◽  
Nikolaos Kantiranis ◽  
Lambrini Papadopoulou ◽  
Eleana Kontonasaki ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Preparation Method ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Dental Restorations ◽  
Gel Technique ◽  
Gel Preparation ◽  
Dental Applications ◽  
Potential Use

The aim of this study was the fabrication using a sol-gel technique of a new glass-ceramic with potential use in dental applications. The characterization of the composition and microstructural properties of the produced material confirmed the similarity between the new sol-gel derived glass-ceramic and a commercial leucite based fluorapatite dental glass-ceramic. The produced material has potential application in dental restorations and it is expected to exhibit better control of composition, microstructure and properties due to the intrinsic advantages of the sol-gel preparation method.

scholarly journals Alumina-Doped Zirconia Submicro-Particles: Synthesis, Thermal Stability, and Microstructural Characterization

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2856 ◽  
Author(s):  
Gregor Thomas Dahl ◽  
Sebastian Döring ◽  
Tobias Krekeler ◽  
Rolf Janssen ◽  
Martin Ritter ◽  
...  
Keyword(s):  
Grain Growth ◽  
Sol Gel ◽  
Microstructural Characterization ◽  
Alumina Content ◽  
Stabilizing Agents ◽  
Precise Control ◽  
Size And Shape ◽  
Elemental Analyses ◽  
Sol Gel Synthesis ◽  
And Control

Zirconia nanoceramics are interesting materials for numerous high-temperature applications. Because their beneficial properties are mainly governed by the crystal and microstructure, it is essential to understand and control these features. The use of co-stabilizing agents in the sol-gel synthesis of zirconia submicro-particles should provide an effective tool for adjusting the particles’ size and shape. Furthermore, alumina-doping is expected to enhance the particles’ size and shape persistence at high temperatures, similar to what is observed in corresponding bulk ceramics. Dispersed alumina should inhibit grain growth by forming diffusion barriers, additionally impeding the martensitic phase transformation in zirconia grains. Here, alumina-doped zirconia particles with sphere-like shape and average diameters of ∼ 300 n m were synthesized using a modified sol-gel route employing icosanoic acid and hydroxypropyl cellulose as stabilizing agents. The particles were annealed at temperatures between 800 and 1200 ∘ C and characterized by electron microscopy, elemental analysis, and X-ray diffraction. Complementary elemental analyses confirmed the precise control over the alumina content (0–50 mol%) in the final product. Annealed alumina-doped particles showed more pronounced shape persistence after annealing at 1000 ∘ C than undoped particles. Quantitative phase analyses revealed an increased stabilization of the tetragonal/cubic zirconia phase and a reduced grain growth with increasing alumina content. Elemental mapping indicated pronounced alumina segregation near the grain boundaries during annealing.

Synthesis and characterization of nickel oxide nanoparticles by sol-gel technique

2020 ◽  
Author(s):  
Infantiya Stephen Grace ◽  
J. Vinola ◽  
Shubramaniyan Deepapriya ◽  
David Rodney John ◽  
A. Aslinjensipriya ◽  
...  
Keyword(s):  
Nickel Oxide ◽  
Sol Gel ◽  
Synthesis And Characterization ◽  
Oxide Nanoparticles ◽  
Nickel Oxide Nanoparticles ◽  
Gel Technique

Coupling Sol-Gel Synthesis and Microwave-Assisted Techniques: A New Route from Amorphous to Crystalline High-Surface-Area Aluminium Fluoride

2008 ◽  
Vol 14 (20) ◽  
pp. 6205-6212 ◽  
Author(s):  
Damien Dambournet ◽  
Gehan Eltanamy ◽  
Alexandre Vimont ◽  
Jean-Claude Lavalley ◽  
Jean-Michel Goupil ◽  
...  
Keyword(s):  
Surface Area ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Microwave Assisted ◽  
Aluminium Fluoride ◽  
Sol Gel Synthesis

Comparison of Several CU(I) and CU(II) Precursors for the Sol-Gel Preparation of High TC Superconducting Metal Oxides

1988 ◽  
Vol 121 ◽  
Author(s):  
Mariquita A. Accibal ◽  
Jonathan W. Draxton ◽  
Allen H. Gabor ◽  
Wayne L. Gladfelter ◽  
Beth Anne Hassler ◽  
...  
Keyword(s):  
Thin Films ◽  
Metal Oxides ◽  
Coordination Compounds ◽  
Sol Gel ◽  
High Tc ◽  
Superconducting Metal ◽  
Zero Resistance ◽  
Gel Preparation ◽  
Sol Gel Synthesis

ABSTRACTA comparison of the use of three different coordination compounds of copper as precursors for the sol-gel synthesis of YBa2Cu3O7-δ has been made. For yttrium, the tris(isopropoxide) was used exclusively, while the use of both Ba(O-i-Pr)2 and Ba(OCH2CH2OEt)2 (prepared in situ from Ba metal) as sources for Ba were studied. After dissolving Y(O-i-pr)3, a Ba source, and the copper(I) alkoxide, [Cu(O-i-Bu)]4, hydrolysis led immediately to an orange gelatinous solid which yielded YBa2Cu3O7-δ upon firing in oxygen. Copper(II) acetate was found to give heterogeneous mixtures under our conditions and was not further studied. Copper(II) acac (acac = acetylacetonate) yielded the best results. Partially hydrolyzed solutions of Cu(acac)2, Ba(OCH2CH2OEt)2, and Y(O-i-pr)3 were spin coated on SrTi03 (100) and fired under oxygen to give oriented (b axis normal to the surface) thin films of YBa2Cu3O7-δ. The onset of superconductivity for the films was 92 K, but they did not reach zero resistance until much lower temperatures.

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