Sol-Gel Processing of Transparent MgAl2O4

1988 ◽  
Vol 121 ◽  
Author(s):  
Yuan-Fu Yu ◽  
Sangvavann Heng ◽  
Tai-Il Mah ◽  
Edward E. Hermes
Keyword(s):  
Sol Gel ◽  
Ceramic Materials ◽  
Metal Alkoxide ◽  
Solvent Ratio ◽  
Processing Conditions ◽  
Chemical Additives ◽  
Control Chemical ◽  
High Degree ◽  
Gel Processing ◽  
Hydrolysis Of

ABSTRACTHigh-purity, transparent monolithic spinel (MgAl2O4) was synthesized via the hydrolytic thermal decomposition of mixed alkoxide organo-metallic precursors. Several factors, such as the metal alkoxide concentration in various solvents, the water to solvent ratio, and the reaction temperatures affect the hydrolysis of the mixed alkoxides. These factors also influence the transparency of the resulting sols and gels. The degree of transparency of the sols and gels is also influenced by such factors as pH and drying control chemical additives. Variations in the processing conditions during drying, aging, and sintering of the gels produced ceramic materials with high degree of transparency.

The Effects of Aluminum Alkoxides on the Synthesis of Composite Powders of Alumina and Titania

1989 ◽  
Vol 155 ◽  
Author(s):  
Michael T. Harris ◽  
Charles H. Byers ◽  
Ronald R. Brunson
Keyword(s):  
Sol Gel ◽  
Particle Morphology ◽  
Ceramic Materials ◽  
Metal Alkoxide ◽  
Oxide Ceramic ◽  
Powder Synthesis ◽  
Composite Powders ◽  
Sol Gel Process ◽  
Hydrolysis Of ◽  
Uniform Composition

ABSTRACTThe synthesis of mixed oxide ceramic powders that consist of very fine (submicron)-monodisperse particles with uniform composition is desirable in the improvement of existing ceramics and the development of new ceramic materials. Metal alkoxide hydrolysis is a very attractive method for the synthesis of ultrapure composite powders at low temperatures by the sol-gel process.The present study investigates the effects of the hydrolysis of aluminum alkoxides and the condensation products on the growth kinetics and morphology of composite particles containing alumina and titania. Alkoxides of titanium and aluminum are employed; therefore, powders of high purity are produced. Since various solvents are used as media for powder synthesis, the effect of the solvent on particle morphology will also be discussed.

Preparation of Multicomponent Ceramic Powders by Sol-Gel Processing

1990 ◽  
Vol 180 ◽  
Author(s):  
J.R. Bartlett ◽  
J.L. Woolfrey
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Processing Conditions ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
X Ray ◽  
Acidic Conditions ◽  
Powder Properties ◽  
Gel Processing ◽  
Hydrolysis Of

ABSTRACTSol-gel methods have been applied to the production of the multicomponent ceramic, Synroc B. These techniques involved the hydrolysis of a mixture of Ti and Zr, alkoxides peptising to form a sol and subsequent sorption of Al3+, Ba2+ and Ca2+ cations under acidic conditions. Powder properties were examined by a variety of techniques, including electron microscopy, x-ray diffraction, N2 sorption, and differential thermal analysis. The effects of processing conditions on the physical properties of the powders are discussed.

Hydrolysis of aluminium metal and sol–gel processing of nano alumina

2004 ◽  
Vol 58 (24) ◽  
pp. 3063-3066 ◽  
Author(s):  
M Thiruchitrambalam ◽  
V.R Palkar ◽  
V Gopinathan
Keyword(s):  
Sol Gel ◽  
Nano Alumina ◽  
Gel Processing ◽  
Hydrolysis Of ◽  
Aluminium Metal

Sol-gel processing and automation of tunable ceramic materials

1993 ◽  
Author(s):  
Fathi Selmi ◽  
Vasundara V. Varadan ◽  
B. Herner ◽  
Vijay K. Varadan
Keyword(s):  
Sol Gel ◽  
Ceramic Materials ◽  
Gel Processing

Chemical Processing and Properties of Nanocrystalline BaTiO3

1992 ◽  
Vol 271 ◽  
Author(s):  
Z. Xu ◽  
H. K. Chae ◽  
M. H. Frey ◽  
D. A. Payne
Keyword(s):  
Grain Size ◽  
Thermal Processing ◽  
Room Temperature ◽  
Sol Gel ◽  
Thin Layers ◽  
Silicon Substrates ◽  
Chemical Processing ◽  
Temperature Structure ◽  
Processing Conditions ◽  
Gel Processing

ABSTRACTBarium titanate (BaTiO3) thin layers were prepared by sol-gel processing. Details are reported for the synthesis route from methoxyethoxide precursors. Partially hydrolyzed solutions were spin-cast onto metallized silicon substrates, and a multilayering technique was used to develop sub-micron structures. Information is reported on the thermal processing conditions used and the development of structure. Crystallization started at 600°C and was fully developed by 700°C. The room temperature structure was cubic, and the grain size was 25–50 nm. Details are reported for the dielectric properties. Ferroelectricity was not observed. Dielectric constant (200–300) increased with increasing grain size, and was stable with respect to temperature, field and frequency. The properties are attractive for potential integrated capacitor applications.

scholarly journals Silane Primers as Adhesion Promotors for Coatings

Proceedings ◽  
2019 ◽  
Vol 29 (1) ◽  
pp. 73
Author(s):  
François Perrin ◽  
Anthony Grard ◽  
Lénaïk Belec
Keyword(s):  
Low Temperatures ◽  
Sol Gel ◽  
Ceramic Materials ◽  
Soft Chemistry ◽  
Molecular Precursors ◽  
Chemistry Method ◽  
Gel Processing

Sol-gel processing is a soft-chemistry method to obtain ceramic materials at low temperatures starting from molecular precursors in solution. [...]

The role of drying-control chemical additives on the preparation of sol-gel derived PLZT thin films

1993 ◽  
Vol 28 (24) ◽  
pp. 6691-6698 ◽  
Author(s):  
De -An Chang ◽  
Yi -Hung Choh ◽  
Wen -Feng Hsieh ◽  
Pang Lin ◽  
Tseung -Yuen Tseng
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Chemical Additives ◽  
Control Chemical ◽  
Plzt Thin Films

Synthesis and Characterization of Ga Doped SiO2 Nanoparticles by a Reverse Micelle and Sol–Gel Processing

2010 ◽  
Vol 11 ◽  
pp. 151-157 ◽  
Author(s):  
Min Yeong Kim ◽  
Min Cheol Chu ◽  
Seong Jai Cho ◽  
Dong Sik Bae
Keyword(s):  
Reverse Micelle ◽  
Sol Gel ◽  
Sio2 Nanoparticles ◽  
Molar Ratio ◽  
Metal Alkoxide ◽  
Hydrolysis And Condensation ◽  
Micro Emulsion ◽  
Average Size ◽  
Gel Processing

Ga doped SiO2 nanosized particles have been synthesized using a reverse micelle technique combined with metal alkoxide hydrolysis and condensation. The size of the particles and the thickness of the coating can be controlled by manipulating the relative rates of the hydrolysis and condensation reactions of tetraethyl orthosilicate(TEOS) within the micro-emulsion. The average size of synthesized Ga doped SiO2 nanoparticles were about in the size range of 10-15 nm and Ga particles 2-5 nm. The effects of synthesis parameters, such as the molar ratio of water to TEOS, and the molar ratio of water to surfactant, are discussed.

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