High temperature characteristic of hydroxyapatite-titania
(1.College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China2.Northwest Institute for Non-ferrous Metal Research, Xi’an 710016, China3.Institute of Analytical Chemistry, Technische Universitt Bergakademie Freiberg, Freiberg 09596, Germany)
Abstract: In order to provide the kinetic mechanism for optimizing the quality of the hydroxyapatite （Ca 10（PO4）6-（OH）2, HA） coating on Ti-alloy orthopedic devices, the high temperature behavior of HA-titania （TiO2） composite specimen was investigated using XRD, FTIR and 31P MAS NMR methods. Thermal treatment of HA-TiO2 mixture powders leads to dehydroxylate and decompound of HA as well as chemical reaction between the two materials. Evidence for the initiation of the dehydroxylation of hydroxyapatite was found at 700℃ in air. The decomposition product of β-tricalcium phosphate was proven at 900℃ in air. Additionally, the formation of CaTiO3, derived from the chemical reaction between HA and titania at 900℃, was confirmed.
Key words: hydroxyapatite； FT-IR spectroscopy； NMR spectroscopy； titania； XRD