Structural Investigation of Sol-Gel-Derived Hybrid Siloxane-Oxide Materials Using 29Si MAS-NMR Spectroscopy

1992 ◽  
Vol 286 ◽  
Author(s):  
F. Babonneau ◽  
L. Bois ◽  
J. Livage ◽  
S. Dire
Keyword(s):  
Single Phase ◽  
Structural Investigation ◽  
Sol Gel ◽  
Structural Models ◽  
Mas Nmr ◽  
Oxide Materials ◽  
29Si Mas Nmr ◽  
Oxide Systems ◽  
Oxide Component ◽  
Phase Systems

ABSTRACTHybrid siloxane-oxide systems were prepared by sol-gel techniques. Siloxane precursors are either monomeric species, dimethyldiethoxysilane, or OH-terminated polydimethylsiloxanes. The oxide component is introduced via metallic alkoxides, M(OR)n (M=Si, Ti, Zr). Transparent materials from flexible to brittle gels, can be obtained over a large M/siloxane range. The structure of the various systems was investigated by 29Si MAS-NMR. The signals due to the difunctional Si units, (CH3)2SiO, depend strongly on the nature of M and on the M/siloxane ratio. Structural models are proposed, ranging from single phase systems with highly interconnected siloxane and oxide units, to nanocomposites made of polysiloxane chains crosslinked with oxide-based particles.

XRD, TEM and 29Si MAS NMR study of sol-gel ZnO-SiO2 nanocomposites

1999 ◽  
Vol 9 (8) ◽  
pp. 1765-1769 ◽  
Author(s):  
Carla Cannas ◽  
Mariano Casu ◽  
Adolfo Lai ◽  
Anna Musinu ◽  
Giorgio Piccaluga
Keyword(s):  
Sol Gel ◽  
Mas Nmr ◽  
29Si Mas Nmr ◽  
Nmr Study ◽  
Sio2 Nanocomposites

Characterisation of sol–gel prepared (HfO2)x(SiO2)1−x (x=0.1, 0.2 and 0.4) by 1H, 13C, 17O and 29Si MAS NMR, FTIR and TGA

2008 ◽  
Vol 33 (1-2) ◽  
pp. 16-24 ◽  
Author(s):  
Luke A. O’Dell ◽  
Philips N. Gunawidjaja ◽  
Mark A. Holland ◽  
Gavin Mountjoy ◽  
Dave M. Pickup ◽  
...  
Keyword(s):  
Sol Gel ◽  
Mas Nmr ◽  
29Si Mas Nmr

29Si, 17O Liquid NMR and 29Si CP-MAS NMR Characterization of Siloxane-Oxide Materials, [(CH3)2SiO/TiO2, (CH3)2SiO/ZrO2]

1994 ◽  
Vol 346 ◽  
Author(s):  
Florence Babonneau
Keyword(s):  
Sol Gel ◽  
Mas Nmr ◽  
Model Systems ◽  
Oxide Materials ◽  
Whole Process ◽  
New Family ◽  
Nmr Characterization ◽  
Potential Applications ◽  
Suitable Technique

ABSTRACTSol-gel derived siloxane oxide materials are an entirely new family of hybrid systems at the frontier between silicones and glasses or ceramics, with a large variety of potential applications. Better control of the chemistry involved in their preparation should lead to an improvement in their properties, and this requires an investigation of the whole process, from the solution to the final materials. Nuclear Magnetic Resonance is a very suitable technique for this purpose, and this paper will give some illustrations on model systems (CH3)2SiO/TiO2, (CH3)2SiO/ZrO2, prepared from dimethyldiethoxysilane and titanium or zirconium alkoxides. It will be focused mainly on the use of 170 solution NMR which clearly shows the formation of Si-O-Ti or Si-O-Zr bonds, but also their disappearance during the aging process. 29Si MAS-NMR spectra of dried gels confirm that the difunctional units are mainly in polydimethylsiloxane chains, and that the system is phase separated. However, the use of cross-polarization techniques involving lK and 29Si nuclei will allow the detection of small number of units in a more constrained environment, certainly close to oxide-based particles.

29Si MAS NMR studies of sol-gel-derived glasses in the Li2OSiO2 system

1990 ◽  
Vol 116 (2-3) ◽  
pp. 161-166 ◽  
Author(s):  
Ch. Wies ◽  
K. Meise-Gresch ◽  
W. Müller-Warmuth ◽  
W. Beier ◽  
U. Wellbrock ◽  
...  
Keyword(s):  
Sol Gel ◽  
Mas Nmr ◽  
29Si Mas Nmr ◽  
Nmr Studies ◽  
Sio2 System

Structural Investigation of Silicalite-I Loaded withn-Hexane by X-ray Diffraction,29Si MAS NMR, and Molecular Modeling

2002 ◽  
Vol 14 (5) ◽  
pp. 2192-2198 ◽  
Author(s):  
Heiko Morell ◽  
Klaus Angermund ◽  
Andrew R. Lewis ◽  
Darren H. Brouwer ◽  
Colin A. Fyfe ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Structural Investigation ◽  
Mas Nmr ◽  
29Si Mas Nmr ◽  
X Ray Diffraction ◽  
X Ray

Effect of MCl (M = Na, K) addition on microstructure and electrical conductivity of forsterite

2020 ◽  
Vol 92 (1) ◽  
pp. 10901
Author(s):  
Saloua El Asri ◽  
Hamid Ahamdane ◽  
Lahoucine Hajji ◽  
Mohamed El Hadri ◽  
Moulay Ahmed El Idrissi Raghni ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Electrical Conductivity ◽  
Single Phase ◽  
Sol Gel ◽  
Complex Impedance ◽  
Transmission Spectra ◽  
Electrical Measurements ◽  
Cation Type ◽  
Edx Analyses ◽  
The Fourier Transform

Forsterite single phase powder Mg2SiO4 was synthesized by sol–gel method alongside with heat treatment, using two different cation alkaline salts MCl as mineralizers (M = Na, K) with various mass percentages (2.5, 5, 7.5, and 10 wt.%). In this work, we report on the effect of the cation type and the added amount of used mineralizer on microstructure and electrical conductivity of Mg2SiO4. The formation of forsterite started at 680–740  °C and at 630–700  °C with KCl and NaCl respectively, as shown by TG-DTA and confirmed by XRD. Furthermore, the Fourier transform infrared (FTIR) transmission spectra indicated bands corresponding to vibrations of forsterite structure. The morphology and elemental composition of sintered ceramics were examined by SEM-EDX analyses, while their densities, which were measured by Archimedes method, increased with addition of both alkaline salts. The electrical measurements were performed by Complex Impedance Spectroscopy. The results showed that electrical conductivity increased with the addition of both mineralizers, which was higher for samples prepared with NaCl than those prepared with KCl.

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