title: Influence of hydrothermal synthesis parameters on the properties of hydroxyapatite nanoparticles.
abstract: Hydroxyapatite (HAp) nanoparticles of tunable diameter were obtained by the precipitation method at room temperature and by microwave hydrothermal synthesis (MHS). The following parameters of the obtained nanostructured HAp were determined: pycnometric density, specific surface area, phase purity, lattice parameters, particle size, particle size distribution, water content, and structure. HAp nanoparticle morphology and structure were determined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). X-ray diffraction measurements confirmed crystalline HAp was synthesized, which was pure in terms of phase. It was shown that by changing the synthesis parameters, the diameter of HAp nanoparticles could be controlled. The average diameter of the HAp nanoparticles was determined by Scherrer's equation via the Nanopowder XRD Processor Demo web application, which interprets the results of specific surface area and TEM measurements using the dark-field technique. The obtained nanoparticles with average particle diameter ranging from 8-39 nm were characterized by having homogeneous morphology with a needle shape and a narrow particle size distribution. Strong similarities were found when comparing the properties of some types of nanostructured hydroxyapatite with natural occurring apatite found in animal bones and teeth.
authors.affiliation: Laboratory of Nanostructures, Institute of High Pressure Physics (UNIPRESS), Polish Academy of Sciences, Sokolowska Street 29/37, 01-142 Warsaw, Poland.
authors.forename: Sylwia
authors.initials: S
authors.lastname: Kuśnieruk
authors.affiliation: Laboratory of Nanostructures, Institute of High Pressure Physics (UNIPRESS), Polish Academy of Sciences, Sokolowska Street 29/37, 01-142 Warsaw, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Wojnarowicz
authors.affiliation: Laboratory of Nanostructures, Institute of High Pressure Physics (UNIPRESS), Polish Academy of Sciences, Sokolowska Street 29/37, 01-142 Warsaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Chodara
authors.affiliation: Laboratory of Nanostructures, Institute of High Pressure Physics (UNIPRESS), Polish Academy of Sciences, Sokolowska Street 29/37, 01-142 Warsaw, Poland.
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Chudoba
authors.affiliation: Laboratory of Nanostructures, Institute of High Pressure Physics (UNIPRESS), Polish Academy of Sciences, Sokolowska Street 29/37, 01-142 Warsaw, Poland.
authors.forename: Stanislaw
authors.initials: S
authors.lastname: Gierlotka
authors.affiliation: Laboratory of Nanostructures, Institute of High Pressure Physics (UNIPRESS), Polish Academy of Sciences, Sokolowska Street 29/37, 01-142 Warsaw, Poland.
authors.forename: Witold
authors.initials: W
authors.lastname: Lojkowski
keywords: hydroxyapatite; microwave hydrothermal synthesis; nanoparticle size control; physical properties of HAp NPs; room temperature synthesis