DANIELA AVRAM, DAN UNGUREANU, NICOLAE ANGELESCU, IONICA IONITA, ANCA GHEBOIANU, IULIAN BANCUTA, ELENA CORINA POPESCU THE STRUCTURAL AND COMPOSITIONAL EVALUATION OF SOME CALCIUM PHOSPHATE GLASSES WITH BIOACTIVE POTENTIAL This paper shows the experimental results of two compositional phosphocalcic glasses: 50% SiO2 - 45% CaO - 5% P2O5 and 47% SiO2 - 45% CaO - 5% P2O5 - 3% Ag2O obtained through sol-gel method. In order to study their bioactivity, the two compositions were structural analyzed by X-ray diffraction method. In this case the apatite formation was highlighted after 14 days of soaked in simulated body fluid, but also other compounds (CaCO3, AgCl and Ag) resulting from the same process were highlighted. The first glass composition is more bioactive than composition doped with silver. The pores of the hydrated silica network are partially clogged by the AgCl formed, which can reduce the rate of hydroxyapatite formation but this process does not cancel the bioactivity of the doped glass. The functional groups present in the structure of those two glasses before and after soaking (PO43-, CO32- and HO-) were highlighted by the Fourier Transform Infrared Spectroscopy (FTIR). The elemental chemical composition was confirmed by elemental analysis WD-XRF. The particle size and the two samples stability was analyzed by Dynamic Light Scattering (DLS), Thermogravimetric Analysis (TG) and Differential Scanning Calorimetry (DSC). The granulometric analysis shows that the glass particles have average diameters of 647.9 nm for the first composition, respectively 380.4 nm for glass doped with silver. TG analysis show a total loss of weight of 8.3% for the first glass, respectively 3.72% for doped glass, which demonstrates that the two compositions are thermally stable.