On-Line Spectroscopic Studies of Group iv Alkoxides and their Interactions with Polymerizable Organic Additives During the Sol-Gel Process

1998 ◽  
Vol 519 ◽  
Author(s):  
R. Cinier ◽  
J. Guilment ◽  
O. Poncelet ◽  
S. Truchet ◽  
D. Wettling
Keyword(s):  
Sol Gel ◽  
Nir Spectroscopy ◽  
Relevant Information ◽  
Spectroscopic Studies ◽  
Organic Additives ◽  
Hydrolysis Process ◽  
Sol Gel Process ◽  
On Line ◽  
Versatile Technique ◽  
Ir And Raman

AbstractThe monitoring of different reactions such as the stabilization of the alkoxides with polymerizable organic additives, the building of the inorganic network during the hydrolysis process, and in a same manner, the polymerization of the organic additives, can be of great importance for the development of hybrid materials with improved processability.NIR spectroscopy is a very versatile technique but lacks of specificity. IR and Raman give more interpretative results but are not always easy to run on a process. We used both techniques along with chemometric tools to extract relevant information from our processes. Then 2D correlation allowed to benefit from the specificity of IR and Raman to develop robust NIR methods able to be used on line to control the different steps of the sol-gel process.The hydrolysis of mixed species of titanium containing chloro, isopropoxo and methacrylato ligands will be discussed in terms of mechanism occuring during the sol-gel process.

Spectroscopic Studies of Chemical Reactions and Dynamics in Sol-Gel Matrices

1994 ◽  
Vol 346 ◽  
Author(s):  
F. Akbarian ◽  
B. Dunnt ◽  
P.D. Fuquat ◽  
J. Mckiernan ◽  
E. Simoni ◽  
...  
Keyword(s):  
Chemical Reactions ◽  
Optical Materials ◽  
Copper Phthalocyanine ◽  
Sol Gel ◽  
Spectroscopic Studies ◽  
Pump Probe ◽  
Silica Monoliths ◽  
Sol Gel Process ◽  
Different Types ◽  
Gel Glasses

ABSTRACTThe synthesis of sol-gel glasses containing organic and organometallic molecular dopants has been well established as an approach for creating new optical materials. Some of these properties are dependent upon chemical reactions which occur in porous xerogel matrices during the sol-gel process or when encapsulated molecules are exposed to other molecules in solution. In this paper, the study of two different types of chemical reactions in the pores of xerogel matrices is reported. In one case copper phthalocyanine is used to characterize dimerization within the pores. The results show that dimer formation is most likely to occur towards the end of the drying stage as the dye concentration in the pores increases from solvent evaporation. A second example involves the use of a pump-probe technique to determine the rate of proton recombination inside the pores of silica monoliths. The behavior of sols and gels is similar to aqueous solution while recombination of protons in the xerogel seems to be affected by the walls of the pores.

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.

Modified colloidal sol–gel process for fabrication of titania nanofiltration membranes with organic additives

2015 ◽  
Vol 476 ◽  
pp. 432-441 ◽  
Author(s):  
Yuanyuan Cai ◽  
Yi Wang ◽  
Xianfu Chen ◽  
Minghui Qiu ◽  
Yiqun Fan
Keyword(s):  
Sol Gel ◽  
Organic Additives ◽  
Nanofiltration Membranes ◽  
Sol Gel Process

Anti-reflection and anti-static (AR/AS) coatings made by TiO2 sol-gel process with poly(3,4-ethylenedioxy thiophene)

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Won Jung Kim ◽  
Tae Young Kim ◽  
Chin Su Park ◽  
Jong Eun Kim ◽  
Tae Hee Lee ◽  
...  
Keyword(s):  
Refractive Index ◽  
Sol Gel ◽  
Nir Spectroscopy ◽  
High Refractive Index ◽  
Conducting Layer ◽  
Uv Curable ◽  
Sol Gel Process ◽  
Refractive Index Layer ◽  
Poly Ethylene ◽  
Low Refractive Index

AbstractIn this study, we designed a two-layer hybrid Anti-Reflection/Anti-Static (AR/AS) thin film. Two kinds of UV-curable fluorinated compounds were synthesized as low refractive index materials, and a TiO2 sol combined with a conducting polymer, poly(3,4-ethylenedioxythiophene) was made by the sol-gel process for use as a high refractive index material as well as a conducting layer. In order to determine the most optimized AR/AS system, the spectral properties were simulated with the refractive index of each layer. According to the simulated results, a high refractive index layer was deposited on the hard coated poly(ethylene terephthalate) (PET) substrate by the spin coating technique, and a low refractive index layer was spin coated on the low refractive index layer. The reflectance and transmittance were measured by UV-VIS-NIR spectroscopy. It was found that the measured reflectance and the maximum transmittance of the AR/AS film were 0.71 %R at a wavelength of 550 nm and 93 %T in the wavelength range between 400 and 700 nm, respectively. The surface resistance of the AR/AS film was 108.6 ohms.

Polymetallic Alkoxides - Precursors for Ceramics

1988 ◽  
Vol 121 ◽  
Author(s):  
Ram C. Mehrotra
Keyword(s):  
Molecular Level ◽  
Sol Gel ◽  
Ceramic Materials ◽  
Metal Alkoxides ◽  
Mixed Solution ◽  
Oxide Ceramics ◽  
Chemical Bonds ◽  
Initial Cost ◽  
Hydrolysis Process ◽  
Sol Gel Process

ABSTRACTBeginning with the work of Dislich, metal alkoxides have been increasingly used for the preparation of oxide-ceramics by the ‘sol-gel’ process. In spite of higher initial cost of alkoxides, their main advantages are (i)homoge-neous mixing at molecular level in the initial solution; (ii)ease of hydrolysis; and (iii) lower sintering temperatures.Although the formation of new chemical bonds between different alkoxides employed in the starting mixed solution has been envisaged, the actual isolation of a large variety of polymetallic alkoxides in our laboratories has given an entirely new turn to the expectations (e.g., preparation of spinel from magnesium bis-tetraalkoxyaluminates) from this process. Some such possibilities are being presented for synthesis of novel ceramic materials.Reactions of polymetallic alkoxides with water, alcohols andβ-diketones would be discussed to throw light on their hydrolysis process in the presence of other alcohols and chelating ligands.

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