A modified random network model for P2O5–Na2O–Al2O3–SiO2 glass studied by molecular dynamics simulations

Zhao, Yaxian; Du, Jincheng; Cao, Xin; Zhang, Chong; Xu, Gang; Qiao, Xvsheng; Liu, Yong; Peng, Shou; Han, Gaorong

doi:10.1039/d0ra10810c

Cited by 17 publications

(9 citation statements)

References 52 publications

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“…For 5.17 mol% < P 2 O 5 content < 8.62 mol% (3 < x < 5), phosphorus broke the connection of Si–O BO –Si and Si–O BO –Al to form Si–O BO –P and Al–O BO –P linkages, indicating that the Si–O BO –P and Al–O BO –P linkages are energetically more favorable. It is also confirmed by Zhao's work 44 . They have found that Al–O–P and Si–O–Al linkages are preferred over other connections.…”

Section: Resultssupporting

confidence: 64%

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Ab initio molecular dynamics simulation of structural and elastic properties of SiO₂–P₂O₅–Al₂O₃–Na₂O glass

et al. 2022

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The effects of P 2 O 5 content on the structural and mechanical properties of phosphoaluminosilicate glasses were studied using ab initio molecular dynamics simulations. Structural simulations involving the partial radial distribution functions, angle distributions, and proportions of bridging oxygen and nonbridging oxygen species were performed. The results indicated that an increase in the phosphorus content disordered the distributions of the bond length and bond angle. At low phosphorus contents (P 2 O 5 < 5.17 mol%), phosphorus captured sodium ions in the Si-O NBO -Na linkage and formed a P-O NBO -Na linkage, completing the silicate network. With P 2 O 5 contents ranging from 5.17 mol% to 8.62 mol%, PO 4 units existed in the glass network in the form of Si-O BO -P and Al-O BO -P linkages. At higher phosphorus contents (18.97 mol% < P 2 O 5 < 50.00 mol%), silicate glass network transformed into a phosphate glass network, the negative charge generated by AlO 4 units was compensated by Al-O BO -P linkage. In particular, the generation mechanisms of oxygen triclusters and five-coordinate aluminum as well as their evolutions were elaborated. Regarding the mechanical properties, atomic bonding strength was examined to analyze the intrinsic nature of the elastic modulus in phosphoaluminosilicate glass. The results indicated that P-O bonding strength significantly contributed to the elastic modulus.

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Section: Resultssupporting

confidence: 64%

“…It is also confirmed by Zhao's work. 44 They have found that Al-O-P and Si-O-Al linkages are preferred over other connections. Accordingly, phosphorus is more likely to connect to a stable SiO 4 tetrahedron and simultaneously generate Si-O BO -P linkages.…”

Section: Bo and Nbomentioning

confidence: 99%

Ab initio molecular dynamics simulation of structural and elastic properties of SiO₂–P₂O₅–Al₂O₃–Na₂O glass

et al. 2022

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“…In the phosphate-free glasses, sodium is assumed to act as charge-compensator for aluminate ([AlO 4 ] − ) groups. Here, each sodium ion is coordinated with approximately six or more BO ions, − each belonging to Si–O–Si or Si–O–Al bonds (rather than a direct link between one Na + and one [AlO 4 ] − ). The key to interpreting the FIR band shifts is the first coordination shell of sodium.…”

Section: Resultsmentioning

confidence: 99%

Influence of Phosphate on Network Connectivity and Glass Transition in Highly Polymerized Aluminosilicate Glasses

et al. 2022

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Melt-derived metaluminous (Al/Na = 1) aluminosilicate glasses in the system SiO 2 −Al 2 O 3 −Na 2 O−P 2 O 5 were prepared with P 2 O 5 and SiO 2 contents varying from 0 to 7.5 and 50 to 70 mol %, respectively. The glass structure was investigated by X-ray absorption near edge structure, far-and medium-infrared, and polarized Raman spectroscopic techniques. The results indicate the incorporation of phosphate into the aluminosilicate network not only as partially depolymerized groups but also as fully polymerized groups charge-balanced by aluminate units in Al−O−P bonds. A new analysis method based on polarized Raman spectra in the bending frequency range indicates a preference of phosphate to reorganize the smallest ring structures. Changes in the glass transition temperature with the increase in phosphate content were found to be consistent with the depolymerization of the network structure shown by spectroscopy. By contrast, increasing the silica content by substituting SiO 4 for AlO 4 tetrahedra, while keeping the phosphate content constant, was found to have a negligible effect on network polymerization. Still, the glass transition temperature decreased and correlated with a far-infrared sodium band shift to higher frequency. This was interpreted as local changes in bond strength caused by complex interactions between the different network formers and sodium ions.

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“…Finally at x ≥ 15 they balance the charges of dianionic P 1 units, the formation of which eventually leads to devitrification and formation of crystalline sodium pyrophosphate. It is worth noting, that the structural scenario summarized in Figure is also consistent with recent MD simulation predictions for this system: Al–O–P and Al–O–Si connectivities dominate, while Si–O–P linkages are under-represented. Nonbridging oxygen species are formed preferentially on the phosphate rather than the silicate species.…”

Section: Discussionmentioning

confidence: 99%

“…This study demonstrated a low probability of P–O–Si linkage formation by 29 Si{ 31 P} and 31 P{ 29 Si} rotational echo double resonance (REDOR) spectroscopy. These results were qualitatively confirmed by a subsequent MD simulation study of a wide range of quaternary glass compositions, suggesting again a strong preference of Al–O–Si and Al–O–P linkages and a low probability of Si–O–P or P–O–P linking . These authors pointed out that such bonding preferences may lead to heterogeneity at the nanometric level and beyond, which becomes particularly pronounced for peralkaline glass compositions.…”

Section: Introductionmentioning

confidence: 99%

Network Modifier Effects in Multiple Network Former Glasses: NMR Results on the System 70 SiO₂–7.5 P₂O₅–(22.5 – x)Al₂O₃–xNa₂O (0 ≤ x ≤ 17.5)

Logrado,

Youngman,

Aitken

et al. 2023

J. Phys. Chem. C

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The modification of the glass structure in the system SiO 2 −P 2 O 5 −Al 2 O 3 by Na 2 O has been studied along the composition line 70SiO 2 −7.5P 2 O 5 −(22.5 − x)Al 2 O 3 −xNa 2 O (0 ≤ x ≤ 17.5) using Raman spectroscopy and multinuclear solid state NMR of 29 Si, 31 P, 23 Na, and 27 Al nuclei. Spectral deconvolutions have been proposed based on 31 P/ 23 Na and 31 P/ 27 Al double resonance and 31 P double-quantum filtering experiments, leading to a detailed picture of the short-and medium-range order in this glass system. The structure of these glasses is dominated by a significant bonding preference between formally anionic four-coordinate aluminum Al 4 species and formally cationic phosphate P 4 units (Al−O−P linkages). In the notation used here, the superscript denotes the number of bridging oxygen atoms bound to the network forming unit. The gradual replacement of alumina by sodium oxide initially (I) decreases the amount of higher coordinate aluminum and increases the number of Si−O−Al linkages, which are charge balanced by the sodium ions introduced by Na 2 O. Higher levels of x (II) lead to a partial depolymerization of Al−O−P linkages and the formation of anionic phosphate species (P 2 and P 1 ) strongly interacting with the sodium ions. While Al−O−P linkages continue to be present for these anionic units, (III) some P−O−P linkages are also formed around x = 15.0, leading to the partial crystallization of sodium pyrophosphate at x = 17.5. There is no evidence for any modification of the silica component, which remains of the Si 4 type throughout the glass composition range. The results of the present study highlight the dual role of the sodium ions in the modification of the network structure of this threecomponent network former system in a quantifiable manner.

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A modified random network model for P₂O₅–Na₂O–Al₂O₃–SiO₂ glass studied by molecular dynamics simulations

Abstract: (A) A modified structural model proposed for P2O5-bearing sodium aluminosilicate glasses. (B) Degree of preferred connection (DPC) of different T–O–T network linkage for LAP, MAP and HAP glass compositions with various P2O5 content.

Cited by 17 publications

References 52 publications

Ab initio molecular dynamics simulation of structural and elastic properties of SiO₂–P₂O₅–Al₂O₃–Na₂O glass

Ab initio molecular dynamics simulation of structural and elastic properties of SiO₂–P₂O₅–Al₂O₃–Na₂O glass

Influence of Phosphate on Network Connectivity and Glass Transition in Highly Polymerized Aluminosilicate Glasses

Network Modifier Effects in Multiple Network Former Glasses: NMR Results on the System 70 SiO₂–7.5 P₂O₅–(22.5 – x)Al₂O₃–xNa₂O (0 ≤ x ≤ 17.5)

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A modified random network model for P2O5–Na2O–Al2O3–SiO2 glass studied by molecular dynamics simulations

Abstract: (A) A modified structural model proposed for P2O5-bearing sodium aluminosilicate glasses. (B) Degree of preferred connection (DPC) of different T–O–T network linkage for LAP, MAP and HAP glass compositions with various P2O5 content.

Cited by 17 publications

References 52 publications

Ab initio molecular dynamics simulation of structural and elastic properties of SiO2–P2O5–Al2O3–Na2O glass

Ab initio molecular dynamics simulation of structural and elastic properties of SiO2–P2O5–Al2O3–Na2O glass

Influence of Phosphate on Network Connectivity and Glass Transition in Highly Polymerized Aluminosilicate Glasses

Network Modifier Effects in Multiple Network Former Glasses: NMR Results on the System 70 SiO2–7.5 P2O5–(22.5 – x)Al2O3–xNa2O (0 ≤ x ≤ 17.5)

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A modified random network model for P₂O₅–Na₂O–Al₂O₃–SiO₂ glass studied by molecular dynamics simulations

Ab initio molecular dynamics simulation of structural and elastic properties of SiO₂–P₂O₅–Al₂O₃–Na₂O glass

Ab initio molecular dynamics simulation of structural and elastic properties of SiO₂–P₂O₅–Al₂O₃–Na₂O glass

Network Modifier Effects in Multiple Network Former Glasses: NMR Results on the System 70 SiO₂–7.5 P₂O₅–(22.5 – x)Al₂O₃–xNa₂O (0 ≤ x ≤ 17.5)