EFFECT OF PREPARATION CONDITIONS ON MICROSTRUCTURE OF NANO-HYDROXYAPATITE SYNTHESIZED BY CHEMICAL...

The precipitation method was used to make nano-hydroxyapatite (n-HA) using Ca (NO3)2•4H2O and (NH4)2HPO4. X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy were used to investigate the effects of reaction temperature, pH, and calcination on the microstructure and development of n-HA crystals. The growth mechanism was also discussed at the same time. The findings demonstrated that as the temperature rose, the crystals became more complete and the particle size tended to rise. The development of n-HA crystals is more affected by the pH of the systems. The HA crystallinity and crystal grain size decrease dramatically when the pH value rises. After calcination, crystal size increases, crystallinity increases, and crystal clarity improves. Under the conditions of 40°C, pH=10 for 4 hours, spherical-like n-HA crystals with an average size of 70-80 nm, equal particle size, and good dispersity may be formed. The average Ca/P ratio of the synthesised HA was about 1.85 by precipitation technique, indicating that it belonged to the rich calcium type of HA, according to EDS analysis.

Please see the link :- https://www.ikprress.org/index.php/JACSI/article/view/4037