Connectivity of Q-species in binary sodium-silicate glasses

Gedeon, Ondrej; Liška, Marek; Macháček, Jan

doi:10.1016/j.jnoncrysol.2006.11.028

Cited by 18 publications

(9 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For highly polymerized glasses (NMS10–NMS4), the coexistence of these two bands suggests the presence of two interconnected networks, one being composed of Q 4 species only and one composed of all kind of Q n species (Q 2 , Q 3 , and remaining Q 4 ). This interpretation has been previously proposed for binary sodium–silicate glasses studied by molecular dynamics simulation 63. The appearance of latter network is highly correlated to the network modifiers.…”

Section: Discussionsupporting

confidence: 74%

Structural study of Mg‐bearing sodosilicate glasses by Raman spectroscopy

Trcera

Rossano

Tarrida

2011

J Raman Spectroscopy

View full text Add to dashboard Cite

The presence of magnesium in glasses of geological, medical, and technological interests influences their physicochemical and durability properties. However, the understanding of the role of magnesium is dependent on the combined knowledge of the structural environment of magnesium in the glass or melt and of the silicate network connectivity of the studied systems. In this article, we present a Raman spectroscopic study of the network connectivity of 10 ternary silicate glasses in the system Na 2 O-MgO-SiO 2 and one Mg-free binary silicate glass Na 2 O-SiO 2 . Results obtained at constant polymerization suggest the existence of various Q n units according to the nature of the modifying cation. As polymerization decreases for Na 2 O-MgO-αSiO 2 glasses (labeled as NMSα with α decreasing from 10 to 2), the band associated with Si-O-Si bending in fully polymerized region disappears being gradually replaced by a band attributed to Si-O-Si bending in region containing mainly Q 2 and Q 3 species. For highly polymerized glasses (NMS10-NMS4), the coexistence of these two bands suggests the presence of two interconnected networks. Concomitantly, the signal associated with Q 3 species first increases. For a further decrease of the polymerization, the high wavenumber part of the signal associated with Q 3 species decreases, while the intensity of the high wavenumber part of the band related to Q 2 species increases. This result strongly suggests that magnesium charge-balances preferentially Q 2 species rather than Q 3 species.

show abstract

Section: Discussionsupporting

confidence: 74%

Structural study of Mg‐bearing sodosilicate glasses by Raman spectroscopy

Trcera

Rossano

Tarrida

2011

J Raman Spectroscopy

View full text Add to dashboard Cite

show abstract

“…We speculate that the free oxygen is necessary for sodium clustering to occur and that its abundance should correlate with the degree of Na clustering occurring within the glass. As the Na clustering and percolation channels develop at high alkali contents, as suggested by MD simulations [50], the free oxygen may act to cross link the Na atoms associated with the "proto-channels". The term proto-channel is used here to describe Na clustering during the incipient stage of development of three-dimensional structure over about 6-12 Ǻ (i.e., 2-3 Na atoms bonded to 4-5 oxygens of O br-Na , and O nbr type) that eventually leads to the development of true percolation channels (N3 Na clusters with Na bonded to 4, 5 and 6 oxygen atoms).…”

Section: 4mentioning

confidence: 94%

“…All glasses used for analysis were clear, with no indication of inhomogeneities upon inspection by petrographic microscope, XRD and electron microprobe. The compositions were prepared at 25,33,40,45,50 and 55 mol % Na 2 O, with two separate preparations and analyses conducted on the last composition. Samples were quenched by either air or water (while in a platinium crucible).…”

Section: Methodsmentioning

confidence: 99%

Bridging, non-bridging and free (O2–) oxygen in Na2O-SiO2 glasses: An X-ray Photoelectron Spectroscopic (XPS) and Nuclear Magnetic Resonance (NMR) study

Nesbitt¹,

Bancroft²,

Henderson³

et al. 2011

Journal of Non-Crystalline Solids

261

169

View full text Add to dashboard Cite

“…is introduced it appears to be the behaviour of some Nb 2 O 5 present in glasses from this work, it occurs a unbalanced loads on the network, where Na þ is more required for compensation of loads in this network than in those, where the glassy networks are homogeneous with only a primary former. In this situation, when placing Ca þ in order to unify two segments of the glassy network, it can find each of its bonding with different energy becoming unstable and consequently unifying the network weakly [17][18][19][20]. That would be according to Ca þ leaching mobility which is essential for glasses biocide activity [4].…”

Section: Resultsmentioning

confidence: 99%

Biocide glass based on Nb2O5-SiO-CaO-Na2O system

et al. 2016

View full text Add to dashboard Cite

In this work, glasses based on SiO-CaO-Na 2 O system containing different Nb 2 O 5 contents were developed. Glasses were melted at 1500°C and quenched in a metallic mould. Citotoxicity tests were performed using neutral red uptake methodology and indicated normal cell growth, which enables the use as biomaterial. Biocide activity was evaluated through glass incubation in bacterial suspension (Escherichia coli) at 37°C under shaking. The composition with higher content of SiO 2 and lower content of Nb 2 O 5 presented higher biocide activity and the coefficient of thermal expansion indicate thermal compatibility with stainless steel 316 L and titanium alloys.

show abstract

Connectivity of Q-species in binary sodium-silicate glasses

Cited by 18 publications

References 17 publications

Structural study of Mg‐bearing sodosilicate glasses by Raman spectroscopy

Structural study of Mg‐bearing sodosilicate glasses by Raman spectroscopy

Bridging, non-bridging and free (O2–) oxygen in Na2O-SiO2 glasses: An X-ray Photoelectron Spectroscopic (XPS) and Nuclear Magnetic Resonance (NMR) study

Biocide glass based on Nb2O5-SiO-CaO-Na2O system

Contact Info

Product

Resources

About