ChemInform Abstract: DEHYDRATION OF GELS AND GLASSES IN THE SYSTEMS BORON OXIDE-SILICON DIOXIDE AND ZIRCONIUM OXIDE-SILICON DIOXIDE PREPARED BY THE SOL-GEL PROCESS FROM METAL ALKOXIDES

1985 ◽  
Vol 16 (16) ◽  
Author(s):  
M. NOGAMI
Keyword(s):  
Silicon Dioxide ◽  
Boron Oxide ◽  
Zirconium Oxide ◽  
Sol Gel ◽  
Metal Alkoxides ◽  
Sol Gel Process

scholarly journals Anodizing of Aluminum Coated with Zirconium Oxide by a Sol-Gel Process I. Effect of Heat Treatment on the Formation of the Anodic Oxide Film

1999 ◽  
Vol 67 (12) ◽  
pp. 1243-1248 ◽  
Author(s):  
Keiji WATANABE ◽  
Masatoshi SAKAIRI ◽  
Hideaki TAKAHASHI ◽  
Katsumi TAKAHIRO ◽  
Shinji NAGATA ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Oxide Film ◽  
Zirconium Oxide ◽  
Sol Gel ◽  
Anodic Oxide ◽  
Anodic Oxide Film ◽  
Sol Gel Process

Hybrid Nanocomposites Based on Metal Oxides and Polysiloxanes with Controlled Morphology

2007 ◽  
Vol 1007 ◽  
Author(s):  
Sorin Ivanovici ◽  
Christoph Rill ◽  
Claudia Feldgitscher ◽  
Guido Kickelbick
Keyword(s):  
Metal Oxides ◽  
Sol Gel ◽  
Hybrid Nanocomposites ◽  
Hybrid Nanoparticles ◽  
Spectroscopic Methods ◽  
Metal Alkoxides ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Ft Ir ◽  
Controlled Morphology

ABSTRACTHybrid materials based on polysiloxanes and metal oxides (SiO2, TiO2, ZrO2) were prepared by hydrosilation of allyl acetoacetate (AAA) modified metal alkoxides (M(OR)4; M = Ti, Zr; R = ethyl, isopropyl) or vinyl triethoxysilane with poly(dimethylsiloxane-co-hydrosiloxane) (PDMS-co-PMHS). The obtained compounds acted as single-source precursors in the sol-gel process. Various spectroscopic methods showed the complete functionalization of the polysiloxane chains with the complexes. When alcohols were used as solvents in the sol-gel process, hybrid nanoparticles were obtained, as observed by dynamic light scattering (DLS) measurements, transmission electron microscopy (TEM), and spectroscopic methods such as NMR and FT-IR.

Study on the Synthesis of Nano-Crystalline Mg2SiO4 Powders by Aqueous Sol-Gel Process

2013 ◽  
Vol 538 ◽  
pp. 142-145 ◽  
Author(s):  
X.F. Chen ◽  
J. Li ◽  
T.T. Feng ◽  
Y.S. Jiang ◽  
X.H. Zhang ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Sol Gel ◽  
Magnesium Nitrate ◽  
Metal Alkoxides ◽  
X Ray Diffraction ◽  
Calcination Process ◽  
X Ray ◽  
Nano Crystalline ◽  
Sol Gel Process ◽  
Scanning Electron

The forsterite-structure Mg2SiO4 was successfully synthesized by the aqueous sol-gel method using Si sols dioxide and magnesium nitrate as starting materials instead of expensive organic solvent and metal alkoxides. The as-prepared nanopowders were characterized by X-ray diffraction (XRD), differential thermal analysis (DTA) and scanning electron microscope (SEM), respectively. The results showed that the calcination process of gel consisted of a series of oxidation and combustion reactions, accompanied by significantly exothermal effects. Highly reactive nanosized Mg2SiO4 powders were successfully obtained at 850 °C with particle size of 60~80 nm.

Zirconium oxide nanoparticles coated on sepiolite by sol–gel process — Their application as a solvent-free catalyst for condensation reactions

2011 ◽  
Vol 89 (3) ◽  
pp. 280-288 ◽  
Author(s):  
Sadok Letaief ◽  
Yun Liu ◽  
Christian Detellier
Keyword(s):  
Clay Mineral ◽  
Zirconium Oxide ◽  
Condensation Reaction ◽  
Sol Gel ◽  
Magic Angle Spinning ◽  
Solvent Free ◽  
Cubic Phase ◽  
Magic Angle ◽  
Solvent Free Conditions ◽  
Sol Gel Process

An inorganic nanocomposite made of zirconia nanoparticles coated on the external surfaces of the fibrous clay mineral sepiolite was prepared by using the sol–gel process under soft conditions using zirconium(IV) propoxide in 1-propanol as the precursor. The resulting materials were characterized by X-ray diffraction (XRD), thermal gravimetric analyses (TGA) and differential thermal analyses (DTA), microporosimetry, 29Si magic-angle spinning (MAS) nuclear magnetic resonance (NMR), and high-resolution transmission electron microscopy (HR-TEM). The organic material from the precursor was fully removed after calcination at 450 °C, concurrently with the crystallization of the cubic phase of zirconium oxide. The coordinated water molecules of sepiolite were fully removed and its symmetrical layered structure was folded after calcination at 650 °C, as observed by XRD and 29Si cross-polarization (CP) / MAS NMR. The arrangement of the nanoparticles of zirconium oxide on the sepiolite external surfaces maintains a fibrous morphology for the nanocomposite. This material was applied as a catalyst for the Knoevenagel condensation reaction of benzaldehyde and malononitrile under solvent-free conditions. Strongly improved yields of reaction, attributed to larger catalytically active surfaces, were obtained compared with either the sepiolite clay mineral or the zirconium oxide tested individually.

Enhanced tribological properties of bismaleimides with a novel hybrid silicon dioxide containing amino groups

2020 ◽  
Vol 32 (10) ◽  
pp. 1150-1159
Author(s):  
Yuan Jia ◽  
Juxiang Yang ◽  
Xue Hu ◽  
Zhen Liu
Keyword(s):  
Silicon Dioxide ◽  
Tribological Properties ◽  
Sol Gel ◽  
Amino Groups ◽  
Silicon Dioxide Nanoparticles ◽  
Friction Process ◽  
Excessive Heat ◽  
Sol Gel Process ◽  
Volume Wear ◽  
Hybrid Silicon

To improve the tribological properties of bismaleimide (BMI) resin, silicon dioxide nanoparticles with imino and terminal functional amino groups were prepared through a sol–gel process to form a novel SiO2-NH2 hybrid. The as-prepared hybrid was then applied as a modifying agent for the BMI matrix to obtain SiO2-NH2/BMI composites. Compared to those of pure BMI resin, the volume wear rate and friction coefficient of the SiO2-NH2/BMI composites decreased significantly, while the wear mechanism changed from fatigue (BMI) to adhesive (SiO2-NH2/BMI) wear. This improvement in the tribological properties of the SiO2-NH2/BMI composites was attributed to the appropriate SiO2-NH2 added content, which endowed the BMI with excellent mechanical and thermal-resistant properties. Thus, the SiO2-NH2/BMI composites could resist the external load and excessive heat during the friction process.

scholarly journals A Brief Review on the Use of Chelation Agents in Sol-gel Synthesis with Emphasis on β-Diketones and β-Ketoesters

2019 ◽  
Vol 33 (3) ◽  
pp. 295-301 ◽  
Author(s):  
Sanislav Kurajica
Keyword(s):  
Ethyl Acetoacetate ◽  
Sol Gel ◽  
Chelating Agent ◽  
Short Review ◽  
Metal Alkoxides ◽  
Structure And Properties ◽  
Gel Structure ◽  
Sol Gel Process ◽  
Rapid Hydrolysis ◽  
Sol Gel Synthesis

Metal alkoxides are the most commonly used sol-gel process precursors. Most<br /> alkoxides show excessive reactivity towards water. That leads to rapid hydrolysis, metal<br /> hydroxide formation, and immediate precipitation. The reactivity of alkoxides can be<br /> reduced by modification with chelation agents. Chelation influences the gelation process,<br /> which is reflected in gel structure and properties of the final material. In this short review,<br /> the chelation process, the oligomerization phenomena, and the influence of the chelating agent on the gel structure are discussed. Peculiarities of the use of FTIR and NMR, as methods particularly suitable for the investigation of chelation process, are described taking ethyl acetoacetate as an example.

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