Properties and structure of RONa2OAl2O3P2O5 (R = Mg, Ca, Sr, Ba) glasses

Byun, Jong–Oh; Kim, Byong-Ho; Hong, Kyoung Sup; Jung, Hyunsung; Lee, Sang‐Won; Izyneev, A. A.

doi:10.1016/0022-3093(95)00280-4

Cited by 103 publications

(57 citation statements)

References 9 publications

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“…[24][25][26][27] The band near 1280 cm À1 is assigned to the asymmetric stretching mode of the two non-bridging oxygen atoms bonded to phosphorus atoms in the Q 2 tetrahedral sites, n as (PO 2 ) À ; the shoulder at 1180 cm À1 is assigned to the symmetric stretch of the same structural unit, n s (PO 2 ) À . The absorption bands near 1100 and 1000 cm À1 are assigned to the asymmetric and symmetric stretching modes of chain-terminating Q 1 groups (n as (PO 3 ) 2À and n s (PO 3 ) 2À ), respectively.…”

Section: Vibrational Spectroscopymentioning

confidence: 99%

“…The band close to 1100 cm À1 has a component at 1150 cm À1 assigned to Q 1 end groups associated with Na þ ions. [25] The absorption band near 900 cm À1 is assigned to the asymmetric stretching modes of the P-O-P linkages, n as (P-O-P), and the bands at 770 and 720 cm À1 assigned to the symmetric stretching modes of these linkages, n s (P-O-P). The broad absorption around 540 cm À1 is attributed to O-P-O deformation modes.…”

Section: Vibrational Spectroscopymentioning

confidence: 99%

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Antimicrobial Gallium‐Doped Phosphate‐Based Glasses

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Neel

et al. 2008

Adv Funct Materials

166

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: Vibrational Spectroscopymentioning

confidence: 99%

Section: Vibrational Spectroscopymentioning

confidence: 99%

Antimicrobial Gallium‐Doped Phosphate‐Based Glasses

Valappil

Ready

Neel

et al. 2008

Adv Funct Materials

166

130

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“…The absorption bands have been assigned according to the literature. [23][24][25][26] assigned to the asymmetric stretching modes of the P-O-P linkages,  as (P-O-P), and the partially split band centred around 750 cm −1 is assigned to the symmetric stretching modes of these linkages,  s (P-O-P). The peak at 540 cm −1 is attributed to OPO deformation modes.…”

Section: Ftir Spectroscopymentioning

confidence: 99%

Preparation, structural characterisation and antibacterial properties of Ga-doped sol–gel phosphate-based glass

et al. 2009

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A sol-gel preparation of Ga-doped phosphate-based glass with potential application in antimicrobial devices has been developed. Samples of composition (CaO) 0.30 (Na 2 O) 0.20-x (Ga 2 O 3 ) x (P 2 O 5 ) 0.50 where x = 0 and 0.03 were prepared, and the structure and properties of the gallium-doped sample compared with those of the sample containing no gallium. Analysis of the 31 P MAS NMR data demonstrated that addition of gallium to the sol-gel reaction increases the connectivity of the phosphate network at the expense of hydroxyl groups. This premise is supported by the results of the elemental analysis which showed that the gallium-free sample contains significantly more hydrogen and by FTIR spectroscopy, which revealed a higher concentration of OH groups in that sample. Ga K-edge EXAFS and XANES data revealed that the gallium ions are coordinated by six oxygen atoms. In agreement with the X-ray absorption data, the high-energy XRD results also suggest that the Ga 3+ ions are octahedrally coordinated with respect to oxygen. Antimicrobial studies demonstrated that the sample containing Ga 3+ ions had significant activity againstStaphylococcus aureus compared to the control.

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“…The two bands appeared at 2922 and 2372 cm −1 are related to ethylene glycol which adsorbed on the surface of samples during the smoothing process. The absorption band appeared at 1269 cm −1 corresponding to a P = O vibration band [29], the ‫ע‬ as (PO 2 ) -asymmetric stretching vibrations at 1170 cm −1 [30], the ν as (PO 3 ) asymmetric stretching mode at 1079 cm −1 , the ν s (PO 3 ) symmetric stretching mode at 974 cm −1 [31], the ν as (P-O-P) groups at 906 cm -1 , the ν s (P-O-P) groups at 775 cm −1 and 731 cm −1 [32] and the band at 506 cm −1 due to the deformation mode of (P-O -) groups [33] overlapped with the third longitudinal optical phonon (3LO) of CdTe. There are some differences between the infrared absorption bands for S1 and S2 samples which reflect some important information about the effect of adding ZnO to the glass matrix.…”

Section: Resultsmentioning

confidence: 99%