Evaluation of the Glass Bioactivity Grade by IR Analysis and the Stevels Parameter

Abstract

The structure of silica-based glasses consists on a disrupted network of SiO4 tetrahedra where network modifiers generate non-bridging oxygen groups (NBO), that play an important role at the initial steps of the bioactive process. Infrared spectroscopy is a sensitive technique to the presence of NBO groups and glass local structure modifications. The infrared study has been complemented with a theoretical approach using the Y Stevels parameter. Moreover, the in vitro bioactivity of the glasses as a function of Y Stevels paremeter has been studied, which can be a finding of a predictive tool for bioactivity of glasses.

Orthophosphate nanostructures in SiO2–P2O5–CaO–Na2O–MgO bioactive glasses

“…These results confirm some optical modes identified by Raman spectroscopy and reveal the FTIR sensitivity for detecting phosphate vibrational bands, which makes evident the complementation of both spectroscopic techniques. All these results obtained by IR and Raman analyses for MDG25 and MDG33 samples are in perfect agreement with previous works [7,16,18,24], except for the observed PO 3À 4 antisymmetric bending mode, which reveals a greater IR activity of phosphate groups.…”

The effect of substitution of Al2O3 and B2O3 for SiO2 on the properties of cover glass for liquid crystal display: Structure, thermal, visco‐elastic, and physical properties

“…was mainly attributed to the bending vibration of Si-O b -Si bonds, 11 whereas high-frequency band at 850 ~ 1230 cm −1 range was assigned to Si-O nb and Si-O b stretching vibration of [SiO 4 ] tetrahedral units Q n , wherein n represents a different number of bridging oxygen (n = 1,2,3,4). 12 Comparing the average number of bridging oxygen Y and the average number of non-bridging oxygen X estimated in Table 2, 13 X decreased and Y increased with the substitution of Al 2 O 3 for SiO 2 , causing the strengthening of Si-O b -Si vibration and the weakening of Si-O nb vibration. Meanwhile, the shoulder peak at around 567 cm −1 referring to the vibration of Si-O nb weakened with the substitution, 14 which was also in accordance with the X value.…”

Influence of the slight adjustment of oxides on the structural and physico-chemical properties of thin film transistor-liquid crystal display substrate glass

“…open sci. 7: 191425 O nb in oxygen polyhedron is expressed by X, the average bridging oxygens O b is expressed by Y, and Z represents the average coordination number of network formers [5][6][7]. As a result of RO/Al 2 O 3 > 1, Al 2 O 3 will be treated as network former.…”

“…As shown in table 1, RO/Al 2 O 3 > 1 and (RO-Al 2 O 3 )/B 2 O 3 < 1, so Al 3+ will mainly exist in the form of an [AlO 4 ] tetrahedron, and B 3+ will enter the network with more [BO 3 ] triangle and less [BO 4 ] tetrahedron. Table 2 shows the average coordination number Z of seven samples, wherein R represents the ratio of oxygen ions and network former ions, X = 2R − Z and Y = 2Z − 2R [5][6][7].…”

“…open sci. 7: 191425 O nb in oxygen polyhedron is expressed by X, the average bridging oxygens O b is expressed by Y, and Z represents the average coordination number of network formers [5][6][7] 2 shows the average coordination number Z of seven samples, wherein R represents the ratio of oxygen ions and network former ions, X = 2R − Z and Y = 2Z − 2R [5][6][7].…”