Preparation and Electrophoretic Deposition of an Yttrium Silicate Precursor Sol

. 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.

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Fabrication and Characterization of Nanocrystalline NiO Prepared by Sol-Gel Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.194-196.476 ◽

2011 ◽

Vol 194-196 ◽

pp. 476-479

Author(s):

Yu Cai ◽

Zhao Yang Wu ◽

Shen Li Zhao ◽

Ji Ne Zhu

Keyword(s):

Crystal Structure ◽

Sol Gel ◽

Chelating Agent ◽

Constant Current ◽

Treatment Technology ◽

Sol Gel Process ◽

Stable Performance ◽

Li Ion ◽

Constant Current Charging

The nano-NiO powder was prepared by sol-gel method combining heat treatment technology and its structure and morphology were explored. In addition, the NiO powder electrochemical properties were tested by constant current charging and discharging. The results show that the stable performance sol can be composed by nickel acetate as source of nickel and PAA as chelating agent. Nano-NiO powder of crystal structure integrity, particle uniformity can be prepared by the sol. The gel decomposes completely and gradually forms nanocrystal at 430οC. Its grain size is gradually increasing when the annealing temperature rise. The nano-NiO powder sintered at 600°C exhibits uniform particle, integrity crystal structure, low aggregation and superior electrochemistry performance and may be used in Li-ion battery as the anode material.

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

MRS Proceedings ◽

10.1557/proc-121-275 ◽

1988 ◽

Vol 121 ◽

Cited By ~ 17

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.

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

Journal of Materials Research ◽

10.1557/jmr.2005.0032 ◽

2005 ◽

Vol 20 (1) ◽

pp. 256-263 ◽

Cited By ~ 8

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.

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Partially Hydrolyzed Alkoxysilanes as Precursors for Silica Aerogels

MRS Proceedings ◽

10.1557/proc-121-685 ◽

1988 ◽

Vol 121 ◽

Cited By ~ 19

Author(s):

T. M. Tillotson ◽

L. W. Hrubesh ◽

I. M. Thomas

Keyword(s):

Sol Gel ◽

Silica Aerogels ◽

Low Density ◽

Density Range ◽

Moist Air ◽

Wide Range ◽

Sol Gel Process ◽

Hydrolysis Of ◽

Highly Porous ◽

Controlled Hydrolysis

ABSTRACTThe classical sol-gel process for synthesizing SiO2 aerogels involves the hydrolysis/condensation of tetraethyoxysilane (TEOS) and/or teramethyoxysilane (TMOS) to produce a gel which can then be super-critically extracted to a low density, highly porous aerogel glass. Controlled hydrolysis of TEOS and TMOS leads to partially hydrolyzed compounds that can be subsequently water processed to form silica aerogels in the density range from .020 to .500 gms/cc. The partially hydrolyzed compounds are stable when sealed from moist air and can be stored for future use.We discuss the controlled conditions used to obtain these compounds and present data that characterize their structure. We detail the procedures for preparing the wide range of aerogel densities. We also report on their use as an adhesive.

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Galvanostatic Electrophoretic Deposition of Yttriumsilicate on C/C-Si-SiC Composites

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.412.243 ◽

2009 ◽

Vol 412 ◽

pp. 243-248

Author(s):

Jana Grosse-Brauckmann ◽

Tanja Damjanović ◽

Christos Argirusis

Keyword(s):

Electrophoretic Deposition ◽

Chemical Vapour ◽

Constant Current ◽

Particle Charge ◽

Low Oxygen ◽

Solid State Method ◽

Yttrium Silicate ◽

Current Densities ◽

Sic Composites ◽

Protection Coating

The use of carbon fibre reinforced carbon composites in oxidizing atmospheres is limited to temperatures below 400 °C. To benefit from their excellent mechanical strength that is still preserved at high temperatures, suitable oxidation protection coating systems have to be developed. Composites which are capillary infiltrated with Si and coated with SiC via chemical vapour deposition show significantly enhanced oxidation resistance. For the increase of service temperature above 1300 °C, high temperature stable materials with low oxygen diffusivities such as yttrium silicates have to complement the SiC coating. The electrophoretic deposition performed under constant current conditions leads to relatively high green densities and therefore good sinterability of the applied coatings. In this work we present the preparation of suspensions, their characterization regarding particle size and electrophoretic mobility for yttrium silicate powder prepared by the solid state method. Depending on particle charge and conductivity of the investigated suspensions iodine is employed to increase particle charge. The use of current densities between 0.5-5mA/cm² leads to smooth and homogeneous layers. Layers sintered as low as 1400 °C for 2h already show promising protection of the C/C-Si-SiC substrate during thermogravimetric analysis.

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Synthesis and characterization of superoleophobic fumed alumina nanocomposite coated via the sol-gel process onto ceramic-based hollow fibre membrane for oil-water separation

Ceramics International ◽

10.1016/j.ceramint.2021.05.319 ◽

2021 ◽

Author(s):

Yusuf Olabode Raji ◽

Mohd Hafiz Dzarfan Othman ◽

Nik Abdul Hadi Sapiaa Md Nordin ◽

Mohd Ridhwan Adam ◽

Khairul Anwar Mohd Said ◽

...

Keyword(s):

Sol Gel ◽

Hollow Fibre ◽

Synthesis And Characterization ◽

Water Separation ◽

Hollow Fibre Membrane ◽

Fibre Membrane ◽

Sol Gel Process ◽

Oil Water Separation ◽

Oil Water

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Characterization of Glycoside Hydrolase Family 5 Proteins in Schizosaccharomyces pombe

Eukaryotic Cell ◽

10.1128/ec.00187-10 ◽

2010 ◽

Vol 9 (11) ◽

pp. 1650-1660 ◽

Cited By ~ 11

Author(s):

Encarnación Dueñas-Santero ◽

Ana Belén Martín-Cuadrado ◽

Thierry Fontaine ◽

Jean-Paul Latgé ◽

Francisco del Rey ◽

...

Keyword(s):

Cell Wall ◽

Schizosaccharomyces Pombe ◽

Protein Characterization ◽

Wall Material ◽

Glycoside Hydrolase Family ◽

Content Type ◽

Hydrolysis Of ◽

Controlled Hydrolysis ◽

Hydrolase Family

ABSTRACT In yeast, enzymes with β-glucanase activity are thought to be necessary in morphogenetic events that require controlled hydrolysis of the cell wall. Comparison of the sequence of the Saccharomyces cerevisiae exo-β(1,3)-glucanase Exg1 with the Schizosaccharomyces pombe genome allowed the identification of three genes that were named exg1 + (locus SPBC1105.05), exg2 + (SPAC12B10.11), and exg3 + (SPBC2D10.05). The three proteins have different localizations: Exg1 is secreted to the periplasmic space, Exg2 is a membrane protein, and Exg3 is a cytoplasmic protein. Characterization of the biochemical activity of the proteins indicated that Exg1 and Exg3 are active only against β(1,6)-glucans while no activity was detected for Exg2. Interestingly, Exg1 cleaves the glucans with an endohydrolytic mode of action. exg1 + showed periodic expression during the cell cycle, with a maximum coinciding with the septation process, and its expression was dependent on the transcription factor Sep1. The Exg1 protein localizes to the septum region in a pattern that was different from that of the endo-β(1,3)-glucanase Eng1. Overexpression of Exg2 resulted in an increase in cell wall material at the poles and in the septum, but the putative catalytic activity of the protein was not required for this effect.

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