Study and characterisation of the alteration and devitrification of CaO-MoO

Bio-glasses with the composition yCaO-(1-y)[xMoO3-(1-x)P2O5] (0 ≤ y ≤ 30; x = 50, 67 mol%) were produced. These materials are used in surgery for applications such as bone replacement in orthopaedics, and dental filling. After insertion, they become covered with a layer of carbonated hydroxyapatite, promoting chemical bonds with bone cells that ensure strong adhesion. An in-depth study of their biological and mechanical properties is planned for medical applications. Our study aims to examine in detail the chemical durability and devitrification process of yCaO-(1-y)[0.5MoO3-0.5P2O5] oxide glasses, while establishing a correlation between their structure and properties. This study analyses the evolution of the dissolution rate <ns0:sc>DR </ns0:sc>as a function of CaO content at variable pH and constant temperature, revealing that the dissolution rate does not vary proportionally with the CaO content. It decreases until it reaches a minimum at 10 mol% CaO, after which any further addition causes an increase in DR. We studied chemical compositions with constant P/Mo ratios and presented the results of X-ray diffraction analyses of the associated glasses. The diffractograms of the crystalline glass for the composition (x = 67; y = 30 mol%) show the formation of crystalline phases: CaMoO4 (JCPDF.08-0144), CaP4O11 (JCPDF.70-2085), MoP2O11 (JCPDF.82-1965) and Mo(PO3)3 (JCPDF.09-0106).