INFLUENCE OF ULTRASONIC TREATMENT ON THE MORPHOLOGY OF HYDROXYAPATITE CRYSTALS

Nanograde needle-like hydroxyapatite (HA) crystals were prepared by a wet chemical precipitation method under atmospheric pressure with ultrasonic technique, using calcium nitrate and diammonium hydrogen phosphate as reactant, deionized water as solvent and ammonia as pH adjusting agent. Influences of ultrasonic treatment on crystal morphology and size of HA under different conditions of the process were studied by transform electron microscopy, X-ray diffraction and infrared spectroscopy. It is found that the shape and the size of HA crystals are changed after ultrasonic treatment . The diameter and length of these needle-like crystals become larger and the clusters of crystals are more clearly . These crystals show a poorly crystallized apatite structure as compared with HA sintered at higher temperature.