Sol–gel synthesis of Al2O3–P2O5glasses: mechanistic studies by solution and solid state NMR

2004 ◽  
Vol 14 (10) ◽  
pp. 1605-1615 ◽  
Author(s):  
Long Zhang ◽  
Hellmut Eckert
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Sol Gel ◽  
Mechanistic Studies ◽  
Sol Gel Synthesis

Sol–gel synthesis of alumina modified by phosphorus: a solid state NMR characterization study

1999 ◽  
Vol 9 (10) ◽  
pp. 2637-2646 ◽  
Author(s):  
Juliette Quartararo ◽  
Michel Guelton ◽  
Monique Rigole ◽  
Jean‐Paul Amoureux ◽  
Christian Fernandez ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Sol Gel ◽  
Characterization Study ◽  
Nmr Characterization ◽  
Sol Gel Synthesis

Sol–gel synthesis, phase composition, morphological and structural characterization of Ca10(PO4)6(OH)2: XRD, FTIR, SEM, 3D SEM and solid-state NMR studies

2016 ◽  
Vol 1119 ◽  
pp. 1-11 ◽  
Author(s):  
Simonas Kareiva ◽  
Vytautas Klimavicius ◽  
Aleksandr Momot ◽  
Jonas Kausteklis ◽  
Aleksandra Prichodko ◽  
...  
Keyword(s):  
Phase Composition ◽  
Solid State ◽  
Structural Characterization ◽  
Solid State Nmr ◽  
Sol Gel ◽  
Nmr Studies ◽  
Sol Gel Synthesis

Sol-gel synthesis of phosphate ceramic composites II

1998 ◽  
Vol 13 (6) ◽  
pp. 1553-1559 ◽  
Author(s):  
Zhicheng Cao ◽  
Burtrand I. Lee ◽  
William D. Samuels ◽  
Li-Qiong Wang ◽  
Gregory J. Exarhos
Keyword(s):  
Reaction Mechanism ◽  
Solid State ◽  
Solid State Nmr ◽  
Sol Gel ◽  
Ceramic Composites ◽  
Direct Reaction ◽  
Tetraethoxy Silane ◽  
Gel Technique ◽  
Sol Gel Synthesis ◽  
First Time

Phosphate ceramics were synthesized using sol-gel technique of direct reaction of P2O5 with tetraethoxy silane (TEOS) or titanium tetraethoxide (Ti(OEt)4). The reaction mechanism of P2O5 and TEOS was deduced using liquid and solid-state NMR. Hexacoordinated silicon in phosphosilicate gels was observed. A specially structured titanium phosphate-layered Ti(HPO4)2 · 2H2O was synthesized for the first time through the sol-gel method. The gelation process and phase transformations were investigated.

Solid State NMR as A Probe of Inorganic Materials:Examples From Glasses and Sol-Gels

2006 ◽  
Vol 984 ◽  
Author(s):  
Paul Guerry ◽  
Donna L Carroll ◽  
Phillips N Gunawidjaja ◽  
Prodipta Bhattacharya ◽  
Daniela Carta ◽  
...  
Keyword(s):  
Solid State ◽  
Phosphate Glass ◽  
Solid State Nmr ◽  
Short Range ◽  
Sol Gel ◽  
The Other ◽  
Disordered Materials ◽  
Structural Sensitivity ◽  
Nmr Data ◽  
Wide Range

AbstractTo understand amorphous and structurally disordered materials requires the application of a wide-range of advanced physical probe techniques and herein a combined methodology is outlined. The relatively short-range structural sensitivity of solid state NMR means that it is a core probe technique for characterizing such materials. The aspects of the solid state NMR contribution are emphasized here with examples given from a number of systems, with especial emphasis on the information available from 17O NMR in oxygen-containing materials. 17O NMR data for crystallization of pure sol-gel prepared oxides is compared, with new data presented from In2O3 and Sc2O3. Sol-gel formed oxide mixtures containing silica have been widely studied, but again the role and effect of the other added oxide varies widely. In a ternary ZrO2-TiO2-SiO2 silicate sol-gel the level of Q4 formation is dependent not only on the composition, as expected, but also the nature of the second added oxide. Sol-gel formed phosphates have been much less widely studied than silicates and some 31P NMR data from xerogel, sonogel and melt-quench glasses of the same composition are compared. The effect of small amounts of added antibacterial copper on phosphate glass networks is also explored.

scholarly journals Sol–Gel Treatments to Flame Retard PA11/Flax Composites

Fibers ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 86 ◽  
Author(s):  
Samyn ◽  
Vandewalle ◽  
Bellayer ◽  
Duquesne
Keyword(s):  
Solid State ◽  
Flame Retardant ◽  
Solid State Nmr ◽  
Flame Retardants ◽  
Sol Gel ◽  
Deposition Method ◽  
One Pot ◽  
Successive Layer ◽  
Coating Methods ◽  
Flame Retardant Properties

This work investigates the efficiency of sol–gel treatments to flame retard flax fabric/PA11 composites. Different sol–gel treatments applied to the flax fabrics were prepared using TEOS in combination with phosphorus and/or nitrogen containing co-precursors (DEPTES, APTES) or additives (OP1230, OP1311). When the nitrogen and the phosphorus co-precursors were used, two coating methods were studied: a ‘one-pot’ route and a successive layer deposition method. For the “one-pot” method, the three precursors (TEOS, DEPTES, and APTES) were mixed together in the same solutions whereas for the different layers deposition method, the three different treatments were deposited on the fibers successively, first the TEOS, then a mix of TEOS/DEPTES, and finally a mix of TEOS/APTES. After deposition, the sol–gel coatings were characterized using scanning electron microscope, electron probe microanalyzer, and 29Si and 31P solid-state NMR. When only TEOS or a mix of TEOS and DEPTES is used, homogeneous coatings are obtained presenting well-condensed Si units (mainly Q units). When APTES is added, the coatings are less homogenous and agglomerates are present. A lower condensation rate of the Si network is also noticed by solid-state NMR. When additives are used in combination with TEOS, the TEOS forms a homogenous and continuous film at the surface of the fibers, but the flame retardants are not well distributed and form aggregates. The flame retardant (FR) efficiency of the different treatments on flax fabrics was evaluated using horizontal flame spread test. The following ranking of the different systems is obtained: TEOS + Additives > TEOS > TEOS + DEPTES ~ TEOS + DEPTES + APTES > multilayers. All the sol–gel coatings improve the flame retardant properties of the flax fabric, except the multilayer treatment. Based on these results, the three most efficient sol–gels were selected to prepare sol–gel-modified flax/PA11 composites. The composite modified with only TEOS showed the best FR properties. Surprisingly, the composite modified with the phosphorus-based flame retardant (AlPi) did not exhibit improved FR properties. This effect was attributed to the fact that the amount of the FR additive deposited on the fabrics was too low.

Sign in / Sign up

Export Citation Format

Share Document