Synthesis and size evolution of 1D hydroxyapatite crystals under surfactant-free hydrothermal conditions

Hydroxyapatite nanoparticulate materials have received a great deal of scientific attention due to their dental and orthopedic applications but simple strategies to control particle characteristics (e.g., surface area, shape and size distribution) are still needed. Among several hydroxyapatite structures, one-dimensional nanoscale materials such as nanowires, nanorods and nanobelts can be synthesized in the presence of specific surfactants added during synthesis in order to alter the particle growth. This contribution is aim to explore strategies to obtain one dimensional hydroxyapatite crystals without the use of surfactants. Particularly, we study the effect of several variables such as temperature, reaction time and pH on shape and size of hydroxyapatite crystals produced under hydrothermal conditions. The results obtained show the formation of hydroxyapatite nanorods as well as some interesting insights about how to control particle sizes in samples obtained at temperatures between 180 °C and 220 °C. These results have potential benefits at the time of producing one dimensional hydroxyapatite crystals in a simple and not expensive way.