STRUCTURE AND CHARACTERIZATION OF SOME HIGH CHEMICALLY RESISTANCE SILICATE GLASSES

摘要

A multi component silicate glasses based on Li?O-MgO-P?O?-SiO? system were synthesized and modified by Na?O /Li?O, SrO /MgO and CaO /SrO replacements. The prepared glasses have been characterized by X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). Additionally, bulk density, microhardness, chemical durability and in vitro bioactivity were evaluated as a function of introducing different alkali and alkaline element substitutions. For comprehension the in vitro bioactivity, the glass samples were soaking in simulated body fluid (SBF) solution at 37°C for 14 days. Scanning electron microscopy coupled with energy-dispersive X-ray (SEM-EDX) and (FTIR) were used to characterize forming hydroxyapatite layer produced on glass specimen surfaces. The results show that Na?O/Li?O and CaO/SrO replacements led to enhance the bioactivity behavior of the glasses. The results are harmonious with a weaker network glass structure consequence of Na?O/Li?O and SrO/MgO replacement in the glasses. However, the glass network connectivity increased with addition of the higher charge to size ratio of Ca~(2+) instead of Sr~(2+). The prepared glass samples had microhardness in the range, 4920-6017 MPa; density values in the range, 2.46-2.78 g/cm3 and the weight loss percent was ranged between 0.72 and 1.67 %.