Silica matrix doped with calcium and phosphate by sol-gel

Abstract

Silica matrices doped with calcium and phosphate at various Ca/P molar ratios were prepared by the hydrolytic sol-gel methodology. Tetraethylorthosilicate (TEOS) was reacted with calcium ethoxide, in the presence of phosphoric acid as catalyst. Eu III ions were added to the resulting silica, in order to obtain structural information. The samples were dried at 50C and characterized before and after contact with Simulated Body Fluid (SBF). The xerogels were analyzed by thermal analysis (TA), X-ray diffraction (XRD), photoluminescence (PL), and scanning electron microscopy (SEM). The PL spectra revealed Eu III lines characteristic of the 5D0 ? 7FJ (J = 0, 1, 2, 3, 4) transition of this ion, and they indicated a nonhomogenous distribution of Eu III in the Ca-P-Si matrix. XRD and SEM confirmed the presence of an amorphous and crystalline system before and after contact of the samples with the SBF solution, and the crystalline phases were ascribed to hydroxyapatite and? ?-calcium triphosphate. The goal of the work is the preparation of a material can be used as biomaterias at low temperature.