The influence of pH and temperature on the morphology of hydroxyapatite synthesized by hydrothermal method

Hydroxyapatite (HA) whiskers and crystals were synthesized by hydrothermal treatment of Ca(OH)2 and CaHPO4·2H2O. Different conditions relative to pH=6–14, temperature=60–140 °C have been investigated in order to ascertain their influence on the HA particle structure and morphology. Results have shown that pH value is a significant parameter variable in altering the morphology. Well elongated particles were obtained on condition that pH=9 and temperature=120 °C. These HA whiskers were single crystals with an aspect ratio>20, a typical diameter and length of 40 and 600 nm, respectively.