Design of Experiments (DOE) for the Optimization of Hydrothermal Synthesis of Hydroxyapatite Nanoparticles

The aim of this work was to investigate the influence of different reaction parameters on the properties of hydroxyapatite (HAp) nanoparticles prepared by the hydrothermal method. The literature data describe widely different experimental conditions for the hydrothermal synthesis of HAp. A specific approach was therefore used to evaluate the statistically influential factors among those described in the literature. The role of each experimental parameter was also discussed within the framework of particle nucleation and crystal growth mechanism. Among the selected variables, temperature and pH were found to be the most significant factors affecting the composition and morphology of the HAp. Moreover, in the present study, different morphologies ranging from rod-like to spherical nanoparticles with various characteristics were successfully obtained, which can be applicable for the preparation of various HAp bioceramics.