Ayşe Özyuğuran

Investigation of Strontium Effect on the Bioactive Behavior of Glasses in the System SiO2-CaO-P2O5-Na2O-SrO

In this study, it was aimed to produce bioactive glasses (SiO2-CaO-P2O5-Na2O-SrO) with the substitution of strontium in different weight percentages. Physical, thermal, and in vitro biological properties of the glasses were studied and compared to each other. In vitro simulated body fluid studies were performed to investigate the bioactivity of the produced glass samples. Scanning electron microscopy, X-ray diffraction, ultraviolet spectroscopy and inductively coupled plasma techniques were used to monitor changes in the glass surface and SBF composition. The results showed that all glasses favored precipitation of calcium phosphate layer when they were soaked in SBF; however bioactivity of the glasses increased with the increase of strontium content in the glasses.

Effect of magnesium salts on the sulphation capacity of limestone slurry

The effect of different magnesium salts such as MgO, MgSO4.7H2O and Mg(OH)2 on the total sulphation capacities of limestone slurries prepared from five different limestone samples was investigated. Sulphation reactions of slurries were conducted at a constant temperature of 323 K in a gaseous mixture consisting of 5% O2, 10% CO2, 0.5% SO2 and a balance of nitrogene by volume. It was found that the total sulphation capacities of limestone slurries increased with the addition of MgO and Mg(OH)2 salts and decreased with the addition of MgSO4.7H2O salt. Depending on the chemical composition of the limestone samples the total sulphation capacities of limestone slurries were increased between 22.30% and 75.00% by MgO addition and between 23.70% and 69.00% by Mg(OH)2 addition.