Quantification of local environments by high-resolution (super 11)B, (super 23)Na, and (super 27)Al solid-state NMR

Article Abstract:

The local structural characteristics of glasses in the system Na(sub 2)O-B(sub 2)O(sub 3)-Al(sub 2)O(sub 3) were investigated using multinuclear magic-angle spinning solid-state nuclear magnetic resonance spectroscopy. The (super 23)Na isotropic chemical shifts were found to vary linearly with Na(sub 2)O concentration, suggesting that the sodium ions are homogeneously distributed over the network and not clustered. Results also revealed the presence of trigonal BO(sub 3/3) units, tetrahedral BO(sub 4/2)(super -) sites and three-coordinate BO(sub 2/2)O(super -) species consisting of nonbridging oxygen.

Molecular structure, Aluminum compounds, Sodium compounds, Glass research, Borates

---

Short- and medium-range order in sodium aluminophosphate glasses: New insights from high-resolution dipolar solid-state NMR spectroscopy

Article Abstract:

High-resolution advanced solid-state nuclear magnetic resonance (NMR) spectroscopy methods are used to investigate the local structure and connectivities of sodium alumino-phosphate glasses in a compositional range that is significantly extended by a sol-gel route. New types of five- and six-coordinated aluminum units that are only weakly connected to phosphorous are formed, while the network modifier is attracted by the phosphate units.

Usage, Phosphates, Nuclear magnetic resonance spectroscopy, Structure, Chemical properties

---

Short and medium range order in sodium aluminoborate glasses. 2. site connectivities and cation distributions studied by rotational echo double resonance NMR spectroscopy

Article Abstract:

A quantitative NMR strategy is developed for the network connectivity and the cation distribution in the sodium aluminoborate glass system. The strategy is based on the analysis of rotational echo double resonance (REDOR) spectroscopy applied to the glasses and the crystalline model compounds Li6Al2(BO3)4, NaBO2 and Na2B4O7.

Science & research, Models, Spectrum analysis, Spectroscopy, Chemical compounds

Similar abstracts:

• Abstracts: Nature of silicon-boron mixing in sodium borosilicate glasses: a high-resolution (super 11)B and (super 17)O NMR study
• Abstracts: Detection and identification of corrosion products of sodium aluminoborosilicate glasses by (super 23)Na MQMAS and (super 1)H-->(super 23)Na CPMAS NMR
• Abstracts: Spectroscopic studies of colloidal solutions of nanocrystalline (Ru(bpy)(sub 3)(super 2+) - zeolite Y. Zeolite-induced solvation effects on excited-state properties of Ru(bpy) (sub 3) (super 2 plus): implications for intrazeolitic photochemical quenching reactions
• Abstracts: An examination of confinement effects in high-silica zeolites. High-pressure stability in ordered mesoporous silicas: rigidity and elasticity through nanometer scale arches
• Abstracts: Adsorption and 2-dimensional association of lithium alkyl dicarbonates on the graphite surface through O(super -1)...Li(super +1)...pie (arene) interactions

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.