Sol-Gel Syntheses and Characterization of BaTi4O9 and BaTiO3-Powders

1988 ◽  
Vol 121 ◽  
Author(s):  
Pradeep P. Phule ◽  
Subhash H. Rkbud
Keyword(s):  
High Purity ◽  
Sol Gel ◽  
Spherical Particles ◽  
Barium Acetate ◽  
Amorphous Precursor ◽  
Sol Gel Process ◽  
Alkoxide Precursor ◽  
Precursor Powders ◽  
Hydrolysis Of

ABSTRACTSol-gel processes for the synthesis of high purity, ultrafine BaTi4O9 and BaTiO3 powders are described. Hydrolysis of an alkoxide precursor derived from barium metal and titanium (IV) isopropoxide resulted in formation of powders consisting of ultrafine (0.2 to 1.0 μm) spherical particles. These amorphous precursor powders were converted to crystalline BaTi4O9 powders (particle size 2–3 μm) by heat treatment at 1100 C. The sol-gel process for the synthesis of BaTiOj powders utilized chemical polymerization between moisture insensitive and relatively inexpensive barium acetate and titanium (IV) isopropoxide in the presence of acetic acid. The gel to ceramic conversion was achieved by firing the gels at 1000 °C to obtain high purity, stoichiometric BaTiO3 powders. The powders were sintered to obtain relatively dense (90 % relative density) ceramic bodies.

Preparation and Electrophoretic Deposition of an Yttrium Silicate Precursor Sol

2009 ◽  
Vol 412 ◽  
pp. 267-272 ◽  
Author(s):  
Jana Grosse-Brauckmann ◽  
Günter Borchardt ◽  
Christos Argirusis
Keyword(s):  
Electrophoretic Deposition ◽  
Sol Gel ◽  
Constant Current ◽  
Particle Charge ◽  
Yttrium Silicate ◽  
Micro Cracks ◽  
Sol Gel Process ◽  
Hydrolysis Of ◽  
Controlled Hydrolysis

. In the present work we used the sol-gel process to prepare Y2SiO5 precursor sols suitable for electrophoretic deposition (EPD). The sol synthesis was performed through the controlled hydrolysis of alkoxide solutions of tetraethoxysilane and yttriumoxoisopropoxide. During sol development emphasis was put on characterization of particles size and zeta potential of the formed aggregates. We succeeded in synthesizing a clear sol containing polymeric aggregates with acceptable particle charge. The electrophoretic deposition on glassy carbon or C/C-SiC slabs led to homogenous layers. At low sol concentrations micro cracks in the deposited layers were observed whereas higher concentrations led to thin and dense layers. During constant current EPD a constant voltage was recorded indicating that the deposited layer does not lead to an increase in resistivity in this kind of EPD system.

Characterization of Anatase Nanocrystal-Precipitated Coatings From (100 − x)SiO2·xTiO2 Gel Films Via The Sol-Gel Process with Boiling Hot Water Treatment

2005 ◽  
Vol 20 (1) ◽  
pp. 256-263 ◽  
Author(s):  
Atsunori Matsuda ◽  
Tatsuo Matoda ◽  
Toshihiro Kogure ◽  
Kiyoharu Tadanaga ◽  
Tsutomu Minami ◽  
...  
Keyword(s):  
Water Treatment ◽  
Sol Gel ◽  
Nucleation And Growth ◽  
High Photocatalytic Activity ◽  
Hot Water ◽  
Hot Water Treatment ◽  
High Transparency ◽  
Sol Gel Process ◽  
Hydrolysis Of

Considerable amounts of anatase nanocrystals were formed on the (100 − x)SiO2·xTiO2 coatings with x of 16.5 and 25 mol% with boiling water treatment, whereas the formation of anatase nanocrystals was not clearly observed for the coatings with x of 50 and 75 mol%. Despite the lower TiO2 content, the coatings with x of 16.5 and 25 mol% showed higher concentration of Si–O–Ti bonds among the coatings. Thus, the hydrolysis of Si–O–Ti bonds and resultant sites should facilitate the nucleation and growth of anatase nanocrystals. High transparency, high photocatalytic activity, and superhydrophilicity were demonstrated for the anatase nanocrystals-precipitated coatings.

The preparation and characterization of transparent nano-sized thermochromic VO2–SiO2 films from the sol–gel process

2004 ◽  
Vol 347 (1-3) ◽  
pp. 138-143 ◽  
Author(s):  
Hua-Kuo Chen ◽  
Hsin-Chin Hung ◽  
Thomas C.-K. Yang ◽  
Sea-Fue Wang
Keyword(s):  
Sol Gel ◽  
Sio2 Films ◽  
Sol Gel Process

ChemInform Abstract: Preparation and Characterization of Machinable Mica Glass-Ceramics by the Sol-Gel Process.

ChemInform ◽  
1989 ◽  
Vol 20 (9) ◽  
Author(s):  
T. HAMASAKI ◽  
K. EGUCHI ◽  
Y. KOYANAGI ◽  
A. MATSUMOTO ◽  
T. UTSUNOMIYA ◽  
...  
Keyword(s):  
Sol Gel ◽  
Glass Ceramics ◽  
Sol Gel Process

Synthesis and characterization of well-defined star polymers via a controlled sol-gel process

1991 ◽  
Vol 24 (6) ◽  
pp. 1431-1434 ◽  
Author(s):  
Timothy E. Long ◽  
Larry W. Kelts ◽  
S. Richard Turner ◽  
Jeffrey A. Wesson ◽  
Thomas H. Mourey
Keyword(s):  
Sol Gel ◽  
Star Polymers ◽  
Synthesis And Characterization ◽  
Sol Gel Process

Infrared Characterization of PMMA-SiO2 Hybrid Glasses Obtained by Sol-Gel Process

2010 ◽  
Vol 1278 ◽  
Author(s):  
L.L. Díaz-Flores ◽  
A. S. López Rodríguez ◽  
P. SifuentesGallardo ◽  
M.A. Hernàndez Rivera ◽  
M.a Garnica Romo ◽  
...  
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
Hybrid Coatings ◽  
Force Microscopy ◽  
Air Atmosphere ◽  
Atomic Force ◽  
Sol Gel Process ◽  
Traditional Process ◽  
And Chemical Properties

AbstractThis work is about the production of hybrid coatings of the system SiO2-PMMA (PMMA, polymethylmethacrylate). These materials have interesting mechanical and chemical properties useful for anticorrosive and wear resistance applications. SiO2-PMMA hybrids were obtained by the sol-gel traditional process, using tetraethylorthosilicate (TEOS) and methylmethacrylate (MMA) by Aldrich Co, as starting reagents. The SiO2:PMMA ratio was varied from 0:1 to about 1:1 at air atmosphere deposition. The coatings were obtained on acrylic sheets and silicon wafers. A diversity of coatings with chemical composition ranging from SiO2 and PMMA to obtain the SiO2-PMMA hybrids were obtained. Infrared (IR) and atomic force microscopy (AFM), were performed to determinate structural and morphological behavior.

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