Influence of kinetic parameters on the textural and chemical properties of silsesquioxane materials obtained by sol-gel process

1999 ◽  
Vol 9 (5) ◽  
pp. 1149-1154 ◽  
Author(s):  
Geneviève Cerveau ◽  
Robert J. P. Corriu ◽  
Cédric Fischmeister-Lepeytre
Keyword(s):  
Kinetic Parameters ◽  
Sol Gel ◽  
Chemical Properties ◽  
Sol Gel Process ◽  
And Chemical Properties

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.

Structuring-agent role in physical and chemical properties of Mo/SiO2 catalysts by sol-gel method

2018 ◽  
Vol 89 (2) ◽  
pp. 416-425
Author(s):  
William Giovanni Cortés-Ortiz ◽  
Alexander Baena-Novoa ◽  
Carlos Alberto Guerrero-Fajardo
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Gel Method ◽  
Sol Gel Method ◽  
Physical And Chemical ◽  
And Chemical Properties

Properties of Nano-Hybrid Sol-Gel Materials Synthesized from Colloidal Silica-Silane Containing Epoxy Silane

2007 ◽  
Vol 336-338 ◽  
pp. 2278-2281 ◽  
Author(s):  
Moon Kyong Na ◽  
Dong Pil Kang ◽  
Hoy Yul Park ◽  
Myeong Sang Ahn ◽  
In Hye Myung
Keyword(s):  
Contact Angle ◽  
Colloidal Silica ◽  
Flat Surface ◽  
Coating Layer ◽  
Sol Gel ◽  
Chemical Properties ◽  
Coating Films ◽  
Initial Stage ◽  
Physical And Chemical ◽  
And Chemical Properties

Three kinds of colloidal silica (CS)/silane sol solutions were synthesized in variation with parameters such as different acidity and reaction time. Sol solutions were prepared from HSA CS/ methyltrimethoxysilane (MTMS), LS CS/MTMS and LS CS/MTMS/γ -Glycidoxypropyltri methoxysilane (ES) solutions. In order to understand their physical and chemical properties, sol-gel coating films were fabricated on glass. Coating films on glass, obtained from LS/MTMS sol, had high contact angle, also, much enhanced flat surface in the case of LS/MTMS sol was observed in comparison with HSA/ MTMS sol. From all sol-gel solutions, seasoning effect of for enhancing properties of sol-gel coating layer on glass was observed while such sol-gel solutions were left for 7days. In initial stage of sol-gel reaction, all most of sol solutions used in this work seem to be unstable, formation of coating films was a little hazy and rough. However, improved coating films as observed in 4days later. LS/MTMS/ES sol solutions were synthesized with ES, adding to LS/MTMS sol. Contact angle of LS/MTMS/ES sol-gel coating films decreased, since ES played a role in forming hydrophilic hydroxyl sol. The elastic portion of coating films prepared from LS/MTMS/ES sol increased with addition of ES, but thermal stability decreased a little.

The Ceramist as Chemist - Opportunities for New Materials

1984 ◽  
Vol 32 ◽  
Author(s):  
D. R. Uhlmann ◽  
B.J.J. Zelinski ◽  
G.E. Wnek
Keyword(s):  
Wide Spectrum ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Glass Ceramics ◽  
Chemical Properties ◽  
Ceramic Materials ◽  
Process Technology ◽  
Chemical Homogeneity ◽  
And Chemical Properties

ABSTRACTThe use of sol-gel techniques to prepare glasses and crystalline ceramics offers outstanding opportunity for breakthroughs in technology. The areas of particular promise include novel glasses; crystallineceramics with exceptional microstructures; coatings for modification of electrical, optical, mechanical and chemical properties; porous media with high surface area and tailored chemistry; ceramic powders with high chemical homogeneity and narrow distributions of particle size; matrix materials in ceramicceramic composites; and a wide spectrum of specialty ceramic materials, ranging from abrasives and fibers to glass ceramics and films. Opportunities in each of these areas will be discussed and related to the advances in understanding and process technology required for their achievement. The theses will be advanced that creative chemistry provides the key to many of these advances, that ceramists simply MUST learn more chemistry, but that we dare not rest from our labors when the chemistry is done.

Modification of Clinoptilolite by Synthetic Zeolite

1993 ◽  
Vol 58 (8) ◽  
pp. 1782-1790
Author(s):  
Ľubomír Medvecký ◽  
Jaroslav Briančin ◽  
Ján Mihalik
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
Methanol Conversion ◽  
Synthetic Zeolite ◽  
Al Content ◽  
Physico Chemical ◽  
Sol Gel Process ◽  
Dta And Tg ◽  
High Al Content ◽  
Selection Of

The sol-gel process allows to modify clinoptilolite by the nucleation of synthetic zeolite. From the viewpoint of methanol conversion, the obtained high Al content nucleation-deposited zeolite decreases the catalytic activity of clinoptilolite. Therefore, it is necessary to optimize the selection of suitable synthetic zeolite as to its composition. Contamination of zeolite surfaces by carbonaceous fragments during catalytic process results from physico-chemical properties of the used and processed zeolite, and according to DTA and TG analysis it significantly affects the readsorption of water vapours and likely also the zeolite activity in methanol conversion.

Thin Anisotropic Coatings Based on Sol-Gel Technology.

1990 ◽  
Vol 180 ◽  
Author(s):  
S. Randall Holmes-Farley ◽  
Lynn C. Yanyo
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
Single Step ◽  
Corrosion Prevention ◽  
Thin Coatings ◽  
Metallic Substrates ◽  
Adhesion Promoters ◽  
Adhesion Promotion ◽  
Physical And Chemical ◽  
And Chemical Properties

ABSTRACTUsing sol-gel technology, thin organic/ceramic (ceramer) coatings have been applied to metal surfaces in order to enhance such surface properties as adhesion promotion and corrosion prevention. Isotropic coatings have been found to be effective in certain applications such as corrosion prevention, but the formation of anisotropic coatings permits greater flexibility over the resulting properties. Isotropic coatings derived from tetraethoxysilane, for example, effectively inhibit corrosion while being only 100 to 1000 Å thick. These coatings do not, however, promote adhesion. Thin coatings made from traditional silane adhesion promoters alone are unable to prevent corrosion of metallic substrates.Using monomers with appropriate reactivities permits the single-step synthesis of anisotropic coatings that can both promote adhesion and prevent corrosion. These types of anisotropic coatings allow the physical and chemical properties of a coating to be varied as a function of distance from the substrate and confer properties to the substrate that would not be possible from a single isotropic coating. The principle behind the construction of these anisotropic coatings is general enough that it can be used in many applications where microengineering of surface structures is important.

scholarly journals Aspects Of Chemistry and Chemical Processing Of Organically Modified Ceramics

1990 ◽  
Vol 180 ◽  
Author(s):  
Helmut K. Schmidt
Keyword(s):  
Molecular Level ◽  
Sol Gel ◽  
Chemical Properties ◽  
Chemical Processing ◽  
Inorganic Component ◽  
Soft Chemistry ◽  
Wide Range ◽  
Low Temperature Processing ◽  
Organically Modified ◽  
And Chemical Properties

ABSTRACTFor the synthesis of composites on a nano or molecular level, chemical or physical methods have to be used since mechanical procedures cannot be employed for these systems. If organics have to be included, low temperature processing has to be used for the synthesis of the inorganic component in order not to damage the organic component. Sol-gel techniques are an appropriate means to synthesize oxidic networks by soft chemistry, and various systems of organically modified ceramics (ORMOCERs) have been developed so far. It has been shown that the synthesis parameter can be used to tailor the material properties in a wide range. A review over the chemistry and chemical properties of ORMOCERs and several examples of material developments will be given.

Preparation and Properties of Porous Apatite-Wollastonite Bioactive Glass-Ceramic

2007 ◽  
Vol 330-332 ◽  
pp. 169-172 ◽  
Author(s):  
Ming Xue ◽  
Jun Ou ◽  
Da Li Zhou ◽  
Dange Feng ◽  
Wei Zhong Yang ◽  
...  
Keyword(s):  
Bioactive Glass ◽  
Stromal Cells ◽  
Glass Ceramic ◽  
Sol Gel ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Polymer Foam ◽  
Physical Chemical ◽  
Sol Gel Process ◽  
Precursor Powders

The porous apatite-wollastonite bioactive glass-ceramic (AW-GG) was made from nano-precursor powders derived from sol-gel process, and shaped by dipping method with polymer foam. The physical-chemical properties, bioactivity and biocompatibility of the materials were studied by means of TG, XRD, SEM, TEM and so on. The bioactivity was investigated in simulated body fluid (SBF) and the biocompatibility was evaluated by co-culturing with marrow stromal cells (MSCs). The result shows that: the particle size of the AW precursor powders is 40~100nm; porous AW GC has three-dimensional pored structure with 300~500um macropores and 2~5um micropores; the materials possess high bioactivity and biocompatibility. Porous AW GC may therefore have great potential application as bone tissue engineering scaffold.

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