Development of a Simple and Cost Effective Modified-Sonochemical Method for the Synthesis of Hydroxyapatite Nanoparticles

Hydroxyapatite is frequently used as a promising biomaterial for the treatment of bone defects as a result of its chemical and crystallographic similarities with the main inorganic component of natural bone. There are different factors during the synthesis process responsible for the final characteristics of apatite such as molar ratio of Ca/P, synthesis temperature, pH reaction mixture, adding the reagent, calcination time. In this paper, using a modified-sonochemical technique the increasing calcining temperature and decreasing reaction time, particle size of hydroxyapatite nanoparticles significantly reduced compared to that of conventional sonochemical technique. Diammonium hydrogen phosphate solution with distilled water, hydrated calcium nitrate solution with ethanol was used as a synthesis precursor and the ratio of Ca/ P was fixed at 1.67. The obtained results indicate that the reaction process completed in less than 1.5 h using an optimum sintering temperature. The X-ray diffraction (XRD) patterns indicated hydroxyapatite crystallites was in the range of 25 nm with increasing sintering temperature up to 700 °C. Microscopic analysis (FESEM) showed that the final morphology of the hydroxyapatite nanoparticles was spherical, in which the particle size was in accordance with the calculated data from XRD analysis.