Sol-Gel Process, Structure, and Properties

ABSTRACTTransition metal oxide gels can be obtained, through a polycondensation process, by acidification of aqueous solutions. Thin layers can be easily deposited onto a substrate. Their electronic and ionic properties could lead to new developments of the sol-gel process. The semiconducting properties of V2O gels can be used for antistatic coatings or electrical switching devices. These gels exhibit a lamellar structure and can be described as particle hydrates. They are fast proton conductors and could behave as a host lattice for intercalation.

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Structure and properties of WO3-doped Pb0.97La0.03(Zr0.52Ti0.48)O3 ferroelectric thin films prepared by a sol-gel process

Journal of Applied Physics ◽

10.1063/1.1999834 ◽

2005 ◽

Vol 98 (3) ◽

pp. 034104 ◽

Cited By ~ 6

Author(s):

Santiranjan Shannigrahi ◽

Kui Yao

Keyword(s):

Thin Films ◽

Sol Gel ◽

Ferroelectric Thin Films ◽

Structure And Properties ◽

Sol Gel Process

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

Chemical and Biochemical Engineering Quarterly ◽

10.15255/cabeq.2018.1566 ◽

2019 ◽

Vol 33 (3) ◽

pp. 295-301 ◽

Cited By ~ 1

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 alkoxides show excessive reactivity towards water. That leads to rapid hydrolysis, metal hydroxide formation, and immediate precipitation. The reactivity of alkoxides can be reduced by modification with chelation agents. Chelation influences the gelation process, which is reflected in gel structure and properties of the final material. In this short review, 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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Structure and Properties of Biomorphous Al/C/TiO/TiC Composite Materials Reinforced with Charcoals Coated in ALD and the Sol-Gel Process

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.275.66 ◽

2018 ◽

Vol 275 ◽

pp. 66-77

Author(s):

Tomasz Tański ◽

Łukasz Krzemiński

Keyword(s):

Composite Materials ◽

Sol Gel ◽

Atomic Layer ◽

Al Alloy ◽

Structure And Properties ◽

Infiltration Process ◽

X Ray ◽

Layer Deposition ◽

Sol Gel Process ◽

Pure Carbon

In this framework, an investigation of biomorphous composite materials was performed. The application of a natural reinforcement allows to obtain biomorphous composite materials. Pine wood samples were subjected to the pyrolysis process in order to obtain carbon char. The samples were subjected to Atomic Layer Deposition and the sol-gel coating process in order to obtain a titanium oxide and titanium carbide coating, respectively. Ti-gel carbon char samples were subjected to ceramisation. Pure carbon char coated with TiO and TiC was infiltrated with an Al alloy. The investigations of the obtained composite materials were performed using light microscopy, transmission and scanning electron microscopy for microstructure determination. Raman spectroscopy and X-ray analysis were performed, along with hardness and tribological tests. Crystallites were detected after infiltration of the porous samples with an Al alloy, which were up to several microns in size, depending on the selected coating. As a result of the investigation on coating samples, a significantly smaller presence of Al carbides was found. An increase of hardness and wear resistance of biomorphous composite materials containing the carbides phase was confirmed. The TiO2coating prevents the occurrence of a reaction during the infiltration process and the formation of Al carbides.

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