Síntese de hidroxiapatita pelo método sol-gel utilizando precursores alternativos: Nitrato de cálcio e ácido fosfórico

Abstract

Hydroxyapatite [Ca10(PO4)6(OH) 2, HA] was synthesized using sol-gel route were used phosphoric acid and calcium nitrate as calcium and phosphorous precursors, respectively and as solvent was using the methanol in the preparation of the sol that later will be used in the obtention apatites coatings on titanium alloys substrates. The sol remained stable and no gelling occurred in ambient environment for over 7 days. The sol became a white gel only after the removal of the solvent at 100°C. The product was calcined in 300°C, 500°C and 700°C and had been characterized by DRX, FT-IR, SEM/EDS and TGA/DSC. The synthesized HA became stable 700°C without any another product. X ray diffraction showed that structure apatite initially appeared at 300°C. The crystal size and the HA content increase with increasing calcination temperature. SEM analysis indicated the presence of pores that are important for biomedical applications, improving to the adhesion between neoformed bone tissue and synthesized apatite, i.e, osseointegration.