Crystallinity Changes of CO3-Apatites in Solutions at Physiological pH

Publisher Website
Google Scholar
Abstract
To study the chemical stability of carbonate-containing apatites in solutions with near-neutral pH, synthetic CO3 apatites with various carbonate contents were prepared at 60 and 80 °C. The crystallinity of CO3 apatites was adopted as an indicator of their chemical stability. Incubation for 1 month in distilled water decreased the carbonate content of CO3 apatites synthesized at 60 °C, and greatly increased the crystallinity along the c axis. In metastable solutions containing Ca2+, HPO42-, and HCO3- ions at physiological pH, the crystallinity along the c axis increased without interference from those ions. These results indicate that CO3, apatites tend to change to more stable apatites with higher crystallinity and lower carbonate content, even in the presence of a high concentration of HCO3- ions.