High-resolution solid-state 29Si and 27Al n.m.r. of aluminosilicate intermediates in the synthesis of zeolite A. Part II

Engelhardt, G.; Fahlke, Β.; Mägi, Μ.; Lippmaa, É.

doi:10.1016/0144-2449(85)90012-0

Cited by 55 publications

(23 citation statements)

References 9 publications

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“…Figure 5b displays 27 Al-MAS NMR spectra of NaA-0 and the associated MgA-1 to MgA-4 samples. One main resonance is detected at 59 ppm corresponding to tetrahedrally coordinated aluminum Al(OSi) 4 as expected for LTA-type zeolite [51]. As the exchange rate increases a broadening of the main resonance is observed and the shape of the peak also becomes dissymmetric indicating a distribution of environment in agreement with 29 Si-MAS NMR results.…”

Section: Solid-state Nuclear Magnetic Resonance (Nmr)supporting

confidence: 82%

“…29 Si-MAS NMR spectra of NaA-0 and the associated MgA-1 to MgA-4 samples are displayed in Figure 5a. One main resonance is detected at −89 ppm corresponding to tetrahedral Si(OAl) 4 species typical of LTA-type zeolite [51]. An additional resonance is seen around −94 ppm accounting for around 4% of the total signal whatever the sample.…”

Section: Solid-state Nuclear Magnetic Resonance (Nmr)mentioning

confidence: 95%

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Influence of the Compensating Cation Nature on the Water Adsorption Properties of Zeolites

et al. 2020

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The influence of the compensating cation (Na+, Li+, Mg2+) nature on the water adsorption properties of LTA and FAU-type zeolites was investigated. Cation exchanges were performed at 80 °C for 2 h using 1 M aqueous solutions of lithium chloride (LiCl) or magnesium chloride (MgCl2). XRF and ICP-OES analyses indicate that the cation exchange yields reach values between 59 to 89% depending on the number of exchange cycles and the nature of the zeolite and cation, while both zeolites structures are preserved during the process, as shown by XRD and solid state NMR analyses. Nitrogen adsorption-desorption experiments indicate a higher available microporous volume when sodium cations are replaced by smaller monovalent lithium cations or by divalent magnesium cations because twice less cations are needed compared to monovalent cations. Up to 15% of gain in the available microporous volume is obtained for FAU-type zeolites exchanged with magnesium cation. This improvement facilitates the adsorption of water with an increase in the water uptake up to 30% for the LTA and FAU type zeolites exchanged with magnesium. These exchanged zeolites are promising for uses in water decontamination because a smaller amount is needed to trap the same amount of water compared to their sodium counterparts.

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Section: Solid-state Nuclear Magnetic Resonance (Nmr)supporting

confidence: 82%

Section: Solid-state Nuclear Magnetic Resonance (Nmr)mentioning

confidence: 95%

Influence of the Compensating Cation Nature on the Water Adsorption Properties of Zeolites

et al. 2020

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“…Amorphous gels prepared ffom solution are being increasingly used as precursors in low temperature synthesis routes for glasses [192, 205--212], and zeolites [213]. The ability of NMR to actas a local probe has aUowed new insights to be gained into these amorphous phases and the structural changes that occur.…”

Section: Aluminosilicate Glasses Gels and Fibresmentioning

confidence: 99%

Application of27Al NMR techniques to structure determination in solids

1993

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Abstraer. There have been great improvements in the quality of 27A1 NMR spectra from solids over the last decade. The impact of this technique on structure determination fora wide range of solids is briefly reviewed. Emphasis is placed on the effects arising from the presence of the quadrupolar interaction and strategies that allow unambiguous spectral interpretation. It is demonstrated that in addition to the chemical shift, the quadrupolar interaction itself can be a rich source of local information about solids. The insight obtalned from 27A1 NMR hato atomic level structure often contains surprises, such that previous models of structure and properties have to be reassessed.

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“…One main resonance is detected at 58 ppm for the NaA samples and at 55 ppm for the MgA samples corresponding to tetrahedrally coordinated aluminum Al(OSi) 4 , as expected for the LTA-type zeolite [ 66 ]. After exchange, a broadening of the main resonance is observed for the MgA sample (535 Hz in comparison to 450 Hz for the NaA sample), indicating a distribution of the environment around the Al atoms.…”

Section: Resultsmentioning

confidence: 86%

“…29 Si MAS NMR spectra of NaA and MgA samples are displayed in Figure 3. One main resonance is detected at −89.5 ppm and −88.9 ppm for the NaA and MgA samples, respectively, corresponding to tetrahedral Si(OAl) 4 species typical of the LTA-type zeolite [66].…”

Section: Local Chemical Structurementioning

confidence: 99%

Zeolite-Polymer Composite Materials as Water Scavenger

et al. 2021

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The influence of the charge compensating cation nature (Na+, Mg2+) on the water adsorption properties of LTA-type zeolites used as filler in composite materials (zeolite/polymers) was investigated. Large scale cation exchanges were performed on zeolite powder at 80 °C for 2 h using 1 M magnesium chloride (MgCl2) aqueous solutions. XRF, ICP, and EDX analyses indicate a successful cationic exchange process without the modification of the zeolite structure as shown by XRD and solid-state NMR analyses. Composite materials (granulates and molded parts) were manufactured using to extrusion and injection processes. In the case of MgA zeolite, nitrogen adsorption–desorption experiments allowed us to measure a microporous volume, unlike NaA zeolite, which is non-porous to nitrogen probe molecule. SEM and EDX analyses highlighted the homogeneous distribution of zeolite crystals into the polymer matrix. Water adsorption capacities confirmed that the trends observed in the zeolite powder samples are preserved after dragging zeolites into composite formulations. Granulates and molded parts composite samples containing the magnesium exchanged zeolite showed an increase of their water adsorption capacity up to +27% in comparison to composite samples containing the non-exchanged zeolite. The MgA composite is more promising for water decontamination applications due to its higher water adsorption properties than the NaA composite.

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High-resolution solid-state 29Si and 27Al n.m.r. of aluminosilicate intermediates in the synthesis of zeolite A. Part II

Cited by 55 publications

References 9 publications

Influence of the Compensating Cation Nature on the Water Adsorption Properties of Zeolites

Influence of the Compensating Cation Nature on the Water Adsorption Properties of Zeolites

Application of27Al NMR techniques to structure determination in solids

Zeolite-Polymer Composite Materials as Water Scavenger

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