Raman and Infrared Study of Metal Alkoxides During Sol-Gel Process

1992 ◽  
Vol 271 ◽  
Author(s):  
O. Poncelet ◽  
J -C. Robert ◽  
J. Guilment
Keyword(s):  
Sol Gel ◽  
Analytical Techniques ◽  
Metal Alkoxides ◽  
Organic Additives ◽  
Chemical Additives ◽  
Reactive Metal ◽  
Infrared Study ◽  
Sol Gel Process ◽  
Hydrolysis Of Metal Alkoxides ◽  
Hydrolysis Of

ABSTRACTOrganic additives are commonly used in sol-gel chemistry [1]. They can operate as stabilizers of reactive metal alkoxides [2] towards hydrolysis or as drying control chemical additives (such as dimethylformamide). These organic compounds and the by-products of sol-gel reactions can drastically modify the physical properties of final oxide materials, so that it is necessary to optimize the use of these additives. The first steps of hydrolysis of metal alkoxides stabilized by organic additives have been studied by many sophisticated analytical techniques which are difficult to use at technical level and often strongly alter the sol-gel reactions [3]. We chose to use FT-Raman and Infrared spectrocopies, which allow to remain as close as possible of the sol-gel process without altering it. The first steps of hydrolysis of group (IVb) metal alkoxides, more particularly titanium, modified by chlorides, carboxylic acids and alkanolamines have been investigated.

Synthesis, Structure and Applications of TiO2 Gels

1986 ◽  
Vol 72 ◽  
Author(s):  
J. Livage
Keyword(s):  
Acetic Acid ◽  
Molecular Level ◽  
Sol Gel ◽  
Titanium Alkoxides ◽  
Chemical Additives ◽  
Display Devices ◽  
Sol Gel Process ◽  
Infra Red ◽  
Tio2 Gels ◽  
Hydrolysis Of

AbstractTiO2 gels are usually obtained through hydrolysis of titanium alkoxides. Chemical additives can however react with the precursor at a molecular level and therefore modify the hydrolysis-condensation reactions. Several examples will be described :acetic acid, acetylacetone or Cr(acac)3. The whole sol-gel process is followed all the way from the precursors to the gel and each step is characterized by spectroscopic experiments (Infra-red, N.M.R, E.S.R.). Some electronic properties of TiO2 gels are then described. Chemical addi-tives allow an optimization of thý sol-gel process according to each speci-fic applications : electrochromic display devices, photoanodes or photoche-mical reactions.

Synthesis, Structure And Applications Of TiO2 Gels

1986 ◽  
Vol 73 ◽  
Author(s):  
J. Livage
Keyword(s):  
Molecular Level ◽  
Sol Gel ◽  
Photochemical Reactions ◽  
Titanium Alkoxides ◽  
Chemical Additives ◽  
Display Devices ◽  
Sol Gel Process ◽  
Infra Red ◽  
Tio2 Gels ◽  
Hydrolysis Of

ABSTRACTTiO2 gels are usually obtained through hydrolysis of titanium alkoxides. Chemical additives can however react with the precursor at a molecular level and therefore modify the hydrolysis-condensation reactions. Several examples will be described :acetic acid, acetylacetone or Cr(acac)3 The whole solgel process is followed all the way from the precursors to the gel and each step is characterized by spectroscopic experiments (Infra-red, N.M.R, E.S.R.). Some electronic properties of TiO2 gels are then described. Chemical additives allow an optimization of the sol-gel process according to each specific applications : electrochromic display devices, photoanodes or photochemical reactions.

Hybrid Nanocomposites Based on Metal Oxides and Polysiloxanes with Controlled Morphology

2007 ◽  
Vol 1007 ◽  
Author(s):  
Sorin Ivanovici ◽  
Christoph Rill ◽  
Claudia Feldgitscher ◽  
Guido Kickelbick
Keyword(s):  
Metal Oxides ◽  
Sol Gel ◽  
Hybrid Nanocomposites ◽  
Hybrid Nanoparticles ◽  
Spectroscopic Methods ◽  
Metal Alkoxides ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Ft Ir ◽  
Controlled Morphology

ABSTRACTHybrid materials based on polysiloxanes and metal oxides (SiO2, TiO2, ZrO2) were prepared by hydrosilation of allyl acetoacetate (AAA) modified metal alkoxides (M(OR)4; M = Ti, Zr; R = ethyl, isopropyl) or vinyl triethoxysilane with poly(dimethylsiloxane-co-hydrosiloxane) (PDMS-co-PMHS). The obtained compounds acted as single-source precursors in the sol-gel process. Various spectroscopic methods showed the complete functionalization of the polysiloxane chains with the complexes. When alcohols were used as solvents in the sol-gel process, hybrid nanoparticles were obtained, as observed by dynamic light scattering (DLS) measurements, transmission electron microscopy (TEM), and spectroscopic methods such as NMR and FT-IR.

Synthesis of Hollow Titania Photocatalytic Particles Using Yeast as Templates

2013 ◽  
Vol 699 ◽  
pp. 126-132 ◽  
Author(s):  
Toshiyuki Nomura ◽  
Syota Tanii ◽  
Hayato Tokumoto ◽  
Yasuhiro Konishi
Keyword(s):  
Pore Diameter ◽  
Sol Gel ◽  
Solid Particles ◽  
Core Shell ◽  
Average Pore ◽  
Inorganic Particles ◽  
Sol Gel Process ◽  
Yeast Powder ◽  
Titania Precursor ◽  
Hydrolysis Of

Hollow inorganic particles have attracted considerable interest for a variety of applications. In this work, yeast powder was used as a bio-template to fabricate yeast/titania core-shell spheres. A titania precursor was deposited via the hydrolysis of tetraisopropyl titanate. Triethanolamine was employed to control the reaction rate of the sol-gel process. The hollow titania particles with a diameter of approximately 4 m and a thickness of approximately 54 nm were successfully obtained after calcination of the core-shell spheres at 700 °C. The crystal structure of the particles was anatase. The specific surface area and the average pore diameter were 21.4 m2/g and 1.6 nm, respectively. The photocatalytic activity of the hollow particles was higher compared with that of solid particles.

Homogeneous phase synthesis of chitosan silica hybrid materials in ionic liquid medium and adsorption of Fe(III) from aqueous solutions

2019 ◽  
Vol 38 (9) ◽  
pp. 586-597 ◽  
Author(s):  
Ananda S. Amarasekara ◽  
Deping Wang
Keyword(s):  
Ionic Liquid ◽  
Hybrid Materials ◽  
Sol Gel ◽  
Phase Reaction ◽  
Phase Synthesis ◽  
Homogeneous Phase ◽  
Sol Gel Process ◽  
Hydrolysis Of ◽  
Silica Hybrid ◽  
Ionic Liquid Medium

Two chitosan silica hybrid materials were prepared by a two-step process in 78–84% yields using the homogeneous phase reaction of 3-(triethoxysilyl)propyl isocyanate with chitosan dissolved in 1-n-butyl-3-methylimidazolium chloride ionic liquid (∼10% w/w), which was followed by NH4OH catalyzed hydrolysis of triethoxysilyl groups and then sol-gel process. These new hybrid materials were shown to adsorb up to about 95% of Fe3+ from 5 × 10−4 M aqueous solution at room temperature in 24 h.

ChemInform Abstract: Synthesis of LiAlO2 Powder by Hydrolysis of Metal Alkoxides

ChemInform ◽  
1987 ◽  
Vol 18 (24) ◽  
Author(s):  
S.-I. HIRANO ◽  
T. HAYASHI ◽  
T. KAGEYAMA
Keyword(s):  
Metal Alkoxides ◽  
Hydrolysis Of Metal Alkoxides ◽  
Hydrolysis Of
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