title: Particle size and shape modification of hydroxyapatite nanostructures synthesized via a complexing agent-assisted route.
abstract: In this work, hydroxyapatite (HAP), Ca10(PO4)6(OH)2, nanostructures including nanorods, nanobundles and nanoparticles have been prepared via a simple precipitation method. In the present method, Ca(NO3)2·4H2O and (NH4)2HPO4 were used as calcium and phosphorus precursors, respectively. Besides, the Schiff bases derived from 2-hydroxyacetophenone and different diamines were used as complexing agents for the in situ formation of Ca(2+) complexes. The formation mechanism of 0-D and 1-D nanostructures of HAP was also considered. When the complexing agents could coordinate to the Ca(2+) ions through N and O atoms to form the [CaN2O2](2+) complexes, HAP nanoparticles were generated. On the other hand, nanorods and nanobundles of HAP were obtained by forming the [CaN2](2+) as well as [CaO2](2+) complexes in the reaction solution. This work is the first successful synthesis of pure HAP nanostructures in the presence of Schiff bases instead of using the common surfactants.
authors.affiliation: Department of Inorganic Chemistry, Faculty of Chemistry, University of Kashan, Kashan, P.O. Box. 87317-51167, Islamic Republic of Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Mohandes
authors.affiliation: Department of Inorganic Chemistry, Faculty of Chemistry, University of Kashan, Kashan, P.O. Box. 87317-51167, Islamic Republic of Iran; Institute of Nano Science and Nano Technology, University of Kashan, Kashan, P.O. Box. 87317-51167, Islamic Republic of Iran. Electronic address: salavati@kashanu.ac.ir.
authors.forename: Masoud
authors.initials: M
authors.lastname: Salavati-Niasari
mesh_terms: D000327:Adsorption; D002118:Calcium / Q000737:chemistry; D056831:Coordination Complexes / Q000737:chemistry; D017886:Durapatite / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry; D010316:Particle Size; D012545:Schiff Bases / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D056831:Coordination Complexes; D012545:Schiff Bases; D017886:Durapatite; D009584:Nitrogen; D002118:Calcium
keywords: Complexing agent; Hydroxyapatite; Nanostructures