Valuation of an effluent: use as raw material in the synthesis of CaO-MgO-SiO2 ceramic powder for biomedical application

Abstract

Glass, ceramic-glass and ceramic bioactive materials have been intensely studied since the discovery of the first Bioactive glass, Bioglass® 45S5, in 1969. Bioactivity is defined as the material interaction with the physiological environment when it is deployed, leading its integration into the living tissue. The bioactivity of ceramics can be evaluated through the surface growth of a layer of hydroxyapatite (HA) related to the mineral phase of bone tissue. Studies show that several compounds calcium silicate glass based exhibit bioactivity in vitro. Although the mechanism of formation of HA is not yet completely elucidated, the presence of silanol groups on the surface of the material seems to be crucial, suggesting that they act as nucleation sites. Recently, ceramics of the CaO-MgO-SiO2 system have been investigated because of their potential application in the biomedical area. Tests in SBF (Simulated Body Fluid), show that the crystalline phases present in this system, induce the formation of HA in their surfaces. Valuation of an effluent of the zirconium ore opening process, by using it as a raw material for the synthesis of bioactive ceramics of the system CaO-MgO-SiO2, is the objective of the present project. A new method of synthesis, sol-gel jointed with precipitation is proposed to obtain ceramics of CaO-MgO-SiO2. Colloidal particles of SiO2 will be obtained by the sol-gel method. Later, magnesium and calcium hydroxides will be co precipitated. The characterization of the obtained products will be performed by analytical techniques such as DRX, SEM and FTIR. In vitro tests will be carried out by dipping the ceramic in SBF to observe its bioactivity. Cytotoxicity test will be made with cells CHO (Chinese hamster ovary). (AU)