Synthesis, characterization and in vitro bioactivity of magnesium-doped sol–gel glass and glass-ceramics

The paper reports the first attempt at changing cooling treatment of synthesizing method in order to investigate its effect on the physical properties of sol-gel derived nano bioactive glass-ceramic in the system 58SiO2-33CaO-9P2O5 (wt.%). We hypothesized that the method of cooling may affect the properties of nano bioactive glass-ceramic. To test this hypothesis, two different method of cooling treatment was applied after calcinations in synthesizing method. Both quenched and unquenched nano bioactive glass-ceramics were soaked in Ringer?s solution with bovine serum albumin (BSA) for bioactivity evaluation. The obtained samples were analyzed for their composition, crystalinity and morphology through X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), surface electron microscope (SEM) and transmission electron microscope (TEM). The SEM images showed that the morphology of nano bioactive glass-ceramics was completely changed by quenching process. Results of in vitro bioactivity evaluation revealed that the unquenched attains faster apatite formation ability than the quenched sample. Other properties of these two morphologically different nano bioactive glass-ceramics were strongly discussed.

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Influence of thermal treatment on the structure and in vitro bioactivity of sol-gel prepared CaO-SiO2-P2O5 glass-ceramics

Processing and Application of Ceramics ◽

10.2298/pac1403155r ◽

2014 ◽

Vol 8 (3) ◽

pp. 155-166 ◽

Cited By ~ 14

Author(s):

Lachezar Radev

Keyword(s):

Thermal Treatment ◽

Calcium Silicate ◽

Sol Gel ◽

Glass Ceramics ◽

In Vitro Test ◽

In Vitro Bioactivity ◽

X Ray ◽

Vitro Test ◽

Sbf Solution

Nowadays there is a substantial practical interest in the in vitro bioactivity of calcium silicate phosphate (CSP) glass-ceramics and carbonate apatite (CO3HA) formation on their surfaces after in vitro test in simulated body fluid (SBF). The main purpose of the presented article is the evaluation of the chemical composition of the gel with nominal composition 70.59 CaO:28.23 SiO2:1.18 P2O5 (mol.%) on the structure, crystallization behaviour and in vitro bioactivity in SBF solution for 14 and 28 days. The prepared glass-ceramics have been synthesized via a polystep sol-gel method. The structure of the obtaining samples was studied by X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). After thermal treatment of the samples XRD confirmed the presence of ?-Ca2SiO4 and Ca15(PO4)2(SiO4)6, and indicated that at 1500?C Ca15(PO4)2(SiO4)6 becomes predominant phase. FTIR revealed the presence of all characteristics bands for calcium silicate phosphate (CSP) bonds. SEM monitors the presence of particles with different morphology. After in vitro test in SBF, FTIR depicted that B-type carbonate containing hydroxyapatite (CO3HA) is preferentially formed on the immersed glass-ceramics. SEMof the precipitated layers showed the presence of HA spheres. The changes in SBF solution after soaking the samples were recorded by inductively coupled plasma atomic emission spectroscopy (ICP-AES).

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