title: Fabrication of dispersible calcium phosphate nanocrystals via a modified Pechini method under non-stoichiometric conditions.
abstract: Various techniques for preparing ceramic nanoparticles have been developed; however, most of them start from a preparation of precursor nanoparticles that are generally amorphous or in poorly crystallized phases. Thermal treatments used to obtain crystalline phases typically result in the sintering of the products into large polycrystals. In this study, we developed a process to fabricate dispersible hydroxyapatite (HAp; Ca10(PO4)6(OH)2) nanocrystals via a modified Pechini method, which is a sol-gel like solid-state synthesis method for the preparation of multicomponent oxides. We demonstrated that the HAp nanocrystals sintered into large polycrystals ranging in size from several tens to several hundreds of microns via a conventional Pechini method using the stoichiometric Ca/P molar ratio of 1.67. When the Ca/P molar ratio in the precursor was >1.67, a mixture of HAp nanocrystals and removable CaO matrix was obtained. The HAp nanocrystals were dispersed in aqueous media mostly in the form of nanoparticles when the amount of CaO matrix was sufficiently greater than the amount of HAp.
authors: Graduate School of Dentistry, Department of Orthodontics, Osaka Dental University, 8-1 Kuzuha-Hanazono, Hirakata, Osaka 573-1121, Japan.
authors: Yuko
authors: Y
authors: Omori
authors: Department of Biomaterials, Osaka Dental University, 8-1 Kuzuha-Hanazono, Hirakata, Osaka 573-1121, Japan. Electronic address: okada-m@cc.osaka-dent.ac.jp.
authors: Masahiro
authors: M
authors: Okada
authors: Department of Biomaterials, Osaka Dental University, 8-1 Kuzuha-Hanazono, Hirakata, Osaka 573-1121, Japan.
authors: Shoji
authors: S
authors: Takeda
authors: Department of Orthodontics, Osaka Dental University, 8-1 Kuzuha-Hanazono, Hirakata, Osaka 573-1121, Japan.
authors: Naoyuki
authors: N
authors: Matsumoto
mesh_terms: D000180:Acrylic Resins; D019343:Citric Acid; D019855:Ethylene Glycol; D006882:Hydroxyapatites / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D010316:Particle Size
chemical_list: D000180:Acrylic Resins; D006882:Hydroxyapatites; D019343:Citric Acid; C006903:carbopol 940; D019855:Ethylene Glycol
keywords: Calcium phosphate; Dispersible; Nanocrystal; Nanoparticle; Pechini method