Structural characterization of glassy phases in the system Na2O–Ga2O3–P2O5 by MAS and solution NMR and vibrational spectroscopy: II. Structure of the phosphate network

Belkébir, A.; Rocha, João; Esculcas, A.P.; Berthet, P.; Gilbert, Bernard; Gabélica, Z.; Llabrès, Gabriel; Wijzen, F.; Rulmont, A.

doi:10.1016/s1386-1425(99)00117-1

Cited by 23 publications

(18 citation statements)

References 14 publications

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“…4III(b)], with a larger change for the Q 1 site than for the Q 2 . This is consistent with a previous study of Ga 2 O 3 -containing sodium phosphate glass [21] and is due to increasing covalency in the P-O-Ga bonding interaction. A similar trend has been observed in CaO-Na 2 O-P 2 O 5 glasses as sodium is replaced by calcium.…”

Section: Nmr Analysissupporting

confidence: 93%

Antimicrobial Gallium‐Doped Phosphate‐Based Glasses

Valappil

Ready

Neel

et al. 2008

Adv Funct Materials

165

130

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Novel quaternary gallium‐doped phosphate‐based glasses (1, 3, and 5 mol % Ga2O3) were synthesized using a conventional melt quenching technique. The bactericidal activities of the glasses were tested against both Gram‐negative (Escherichia coli and Pseudomonas aeruginosa) and Gram‐positive (Staphylococcus aureus, methicillin‐resistant Staphylococcus aureus, and Clostridium difficile) bacteria. Results of the solubility and ion release studies showed that these glass systems are unique for controlled delivery of Ga3+. 71Ga NMR measurements showed that the gallium is mostly octahedrally coordinated by oxygen atoms, whilst FTIR spectroscopy provided evidence for the presence of a small proportion of tetrahedral gallium in the samples with the highest gallium content. FTIR and Raman spectra also afford an insight into the correlation between the structure and the observed dissolution behavior via an understanding of the atomic‐scale network bonding characteristics. The results confirmed that the net bactericidal effect was due to Ga3+, and a concentration as low as 1 mol % Ga2O3 was sufficient to mount a potent antibacterial effect. The dearth of new antibiotics in development makes Ga3+ a potentially promising new therapeutic agent for pathogenic bacteria including MRSA and C. difficile.

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Section: Nmr Analysissupporting

confidence: 93%

Antimicrobial Gallium‐Doped Phosphate‐Based Glasses

Valappil

Ready

Neel

et al. 2008

Adv Funct Materials

165

130

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“…The GPN p sample features major contribution bands centered at 710 cm −1 , 740 cm −1 and 1160 cm −1 . The low frequency bands are assigned respectively to symmetric P‐O‐P bond stretching mode between two Q 2 phosphate tetrahedrons and inside a phosphate tetrahedron dimeric entity, while the high frequency band is related to (PO 2 − ) symmetric stretching vibrations in Q 2 . These considerations are consistent with a majority of Q 2 and Q 1 phosphate entities.…”

Section: Resultssupporting

confidence: 71%

Silver centers luminescence in phosphate glasses subjected to X‐Rays or combined X‐rays and femtosecond laser exposure

Guerineau

Cova

Petit

et al. 2019

Int J of Appl Glass Sci

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The generation of silver species has been investigated in silver‐containing sodo‐gallo‐phosphate glasses subjected to X‐ray irradiations. Radioluminescence spectroscopy has evidenced the presence of isolated and paired silver ions. The proportion of silver pairing is found dominant in ortho‐phosphate glass compositions, compared to poly‐phosphate counterparts. The phosphate glass network is reported to have a decisive impact on X‐Ray photosensitivity and the formation of luminescent silver species, namely Ag2+ hole trap silver ions and Agmx+ silver clusters. The subsistence of femtosecond laser produced silver luminescent structures under X‐Ray irradiation has been demonstrated.

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“…The band due to GaO 4 structural units at about 620 cm À1 and another band at about 398 cm À1 (cm-eV) presumably due to symmetric bending vibrations of Ga-O-P linkages [22,23] could be detected in the spectra of all the glasses. The band at 368 cm À1 is attributed to GaO 6 vibrational groups [24] is also located in the spectra of all the glasses. The intensity is found to be maximum in the glass G 4 .…”

Section: Resultsmentioning

confidence: 78%