Silane Primers as Adhesion Promotors for Coatings

AbstractThe sol-gel processing of appropriated molecular precursors easily leads to a variety of hybrid organic-inorganic materials with intrinsic properties. This approach is increasingly becoming an interesting way to prepare heterogeneous catalysts. The paper will focus on the use of hybrids for the preparation of selective catalytic materials. Two examples of the use of hybrid polysilsesquioxanes polymers will be given. i) The tailoring of the pore structure of silicas, under mild reaction conditions, based on the temporary introduction of different organic substructures in the hybrid network of polysilsesquioxane gels will be discussed. ii) Also the preparation of new chiral hybrid supports for enantioselective catalysis will be presented.

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Sol-Gel Processing of Glasses and Glass-Ceramics for Microelectronic Packaging

MRS Proceedings ◽

10.1557/proc-249-59 ◽

1991 ◽

Vol 249 ◽

Author(s):

M.A. Sriram ◽

P.N. Kumta

Keyword(s):

Dielectric Constant ◽

Thermal Analyses ◽

Sol Gel ◽

Glass Ceramics ◽

Signal Propagation ◽

Ceramic Materials ◽

X Ray Diffraction ◽

Low Dielectric ◽

Heat Treated ◽

Gel Processing

In recent years considerable progress has been made in electronic packaging substrate technology. The future need of miniaturization of devices to increase the signal processing speeds calls for an increase in the device density requiring the substrates to be designed for better thermal, mechanical and electrical efficiency.Fast signal propagation with minimum delay requires the substrate to possess very low dielectric constant. Several glasses and glass-ceramic materials have been identified over the years which show good promise as candidate substrate materials. Among these borophosphate and borophosphosilicate glass-ceramics have been recently identified to have the lowest dielectric constant (3.8). Sol-gel processing has been used to synthesize borosilicate, borophosphosilicate and borophosphate glasses and glass-ceramics using inexpensive boron oxide and phosphorus pentoxide precursors. Preliminary results of the processing of these gels and the effect of volatility of boron alkoxide and its modification on the gel structure are described. X-ray diffraction, Differential thermal analyses and FTIR have been used to characterize the as-prepared and heat treated gels.

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Sol-Gel Processing of Transparent MgAl2O4

MRS Proceedings ◽

10.1557/proc-121-601 ◽

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.

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Sol-Gel Strategies for Controlled Porosity Ceramic Materials: Thin Film and Bulk

MRS Proceedings ◽

10.1557/proc-368-329 ◽

1994 ◽

Vol 368 ◽

Cited By ~ 4

Author(s):

C. Jeffrey Brinker ◽

Rakesh Sehgal ◽

Narayan K. Raman ◽

Sai S. Prakash ◽

Laurent Delatire

Keyword(s):

Thin Film ◽

Sol Gel ◽

Ceramic Materials ◽

Particle Packing ◽

Membrane Reactors ◽

Organic Templates ◽

Controlled Porosity ◽

Processing Techniques ◽

Catalytic Membrane Reactors ◽

Gel Processing

ABSTRACTUsing sol-gel processing techniques it is possible to vary the condensation pathway over wide ranges to form primary species ranging in structure from oligomers to polymers to particles. The porosity of the corresponding dry gels depends on the size and structure of the primary species, the organization of these structures, often by aggregation, to form a gel, and the collapse of the gel by drying. This paper reviews these ideas in the context of forming thin film or bulk specimens. Several strategies are introduced to control porosity on length scales of interest for catalysis and catalytic membrane reactors: 1) aggregation of fractals; 2) management of capillary pressure; 3) surface derivatization; 4) relative rates of condensation and evaporation; 5) the use of organic templates and 6) sintering. These strategies are contrasted with the more traditional particle packing approach to preparing controlled porosity materials.

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Chemical Synthesis of Fine Powders

MRS Bulletin ◽

10.1557/s0883769400060693 ◽

1990 ◽

Vol 15 (1) ◽

pp. 18-25 ◽

Cited By ~ 46

Author(s):

J. Livage ◽

M. Henry ◽

J.P. Jolivet ◽

C. Sanchez

Keyword(s):

High Performance ◽

Colloidal Particles ◽

Sol Gel ◽

Solid Material ◽

Narrow Particle Size Distribution ◽

Molecular Precursors ◽

Inorganic Oxides ◽

Fine Powders ◽

Sol Gel Process ◽

Gel Processing

Interest in the synthesis of submicron monodispersed powders is increasing. Such powders find applications in the ceramic industry when high performance materials are required. Sintering time and temperature can be significantly reduced with powders of narrow particle-size distribution. Fine colloidal particles can be made by a variety of methods, from the vapor phase or the liquid phase.The sol gel process offers new approaches to the synthesis of fine powders. Starting from molecular precursors, such as metal alkoxides or aqueous solutions, an oxide network is obtained via inorganic polymerization reactions. These reactions occur in solution, and the term “sol-gel processing” is often used to describe the synthesis of inorganic oxides by wet chemical methods. It offers many advantages compared to the conventional powder route. One unique advantage is the ability to go all the way from the molecular precursor to the solid material, permitting better control of the entire process and allowing synthesis of “tailor-made” powders.

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Sol-gel processing of actin to obtain homogeneous glasses at low temperatures

Biophysical Chemistry ◽

10.1016/0301-4622(89)80068-7 ◽

1989 ◽

Vol 34 (3) ◽

pp. 311-315 ◽

Cited By ~ 3

Author(s):

Gérard Prulière ◽

Pierre Douzou

Keyword(s):

Low Temperatures ◽

Sol Gel ◽

Gel Processing

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Protective Coatings for Stained Glass

MRS Proceedings ◽

10.1557/proc-123-305 ◽

1988 ◽

Vol 123 ◽

Cited By ~ 2

Author(s):

Mary W. Colby ◽

Ting J. Yuen ◽

J. D. Mackenzie

Keyword(s):

Low Temperatures ◽

Protective Coatings ◽

Sol Gel ◽

Oxide Coating ◽

Scratch Resistance ◽

Stained Glass ◽

Oxide Coatings ◽

Chemical Corrosion ◽

Modified Polymers ◽

Gel Processing

AbstractThe protection of glass against water-initiated chemical corrosion is a significant problem. Presently, organic polymers and inorganically modified polymers are being used to protect art glass. However, the service life and durability of these coatings are not entirely satisfactory. Oxide coatings would offer much greater resistance to water penetration. Water permeability through a polymer coating is some ten orders of magnitude larger than that through an oxide coating. This, coupled with a higher scratch resistance, makes oxide coatings promising candidates for the protection of stained glass. Methods to deposit an oxide on glass at relatively low temperatures include sol-gel processing and vapor deposition. This paper compares the performance of different oxide and non-oxide coatings and presents methods for the deposition of oxide coatings at low temperatures.

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Synthesis of SrRuO3 by Sol-Gel Processing

MRS Proceedings ◽

10.1557/proc-548-587 ◽

1998 ◽

Vol 548 ◽

Cited By ~ 1

Author(s):

Y. Wu ◽

S. Zamani ◽

G. Z. Cao

Keyword(s):

Low Temperatures ◽

Single Phase ◽

Sol Gel ◽

Partial Hydrolysis ◽

Ceramic Powders ◽

Processing Methods ◽

Conductive Oxide ◽

Petri Dishes ◽

Gel Processing ◽

Hydrolysis Of

ABSTRACTElectronic conductive oxide SrRuO3has been synthesized by sol-gel processing. Various precursors were tested and four different processing methods were developed. Stable SrRuO3sols were obtained using these four processing methods with various precursors. It was found that partial hydrolysis of strontium precursors was required to achieve a cross-condensation of ruthenium and strontium, so as to obtain a single phase SrRuO3perovskite at relatively low temperatures. The stable sols were either poured into petri-dishes to form xerogels or dip-coated on substrates to form thin films. Single phase SrRuO3perovskite was obtained after heat-treatment at 800 °C or higher temperatures. TGA/DTA, XRD and SEM were applied to characterize sol-gel derived SrRuO3ceramic powders and films.

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