title: Block-copolymer-assisted synthesis of hydroxyapatite nanoparticles with high surface area and uniform size.
abstract: We report the synthesis of hydroxyapatite nanoparticles (HANPs) by the coprecipitation method using calcium D-gluconate and potassium hydrogen phosphate as the sources of calcium and phosphate ions, respectively, and the triblock copolymer F127 as a stabilizer. The HANPs were characterized using scanning electron microscopy, x-ray diffraction, and nitrogen adsorption/desorption isotherms. Removal of F127 by solvent extraction or calcination alters the structure of HANPs. The solvent-extracted HANPs were single crystals with their 〈001〉 axis oriented along the rod axis of the HANP, whereas the calcined HANPs contained two crystal phases that resulted in a spherical morphology. The calcined HANPs had much higher surface area (127 m2g-1) than the solvent-extracted HANPs (44 m2g-1).
authors.affiliation: Department of Bioenvironmental Engineering and R&D Center for Membrane Technology, Chung Yuan Christian University, No. 200, Chung Pei Road, Chung Li 32023, Taiwan.
authors.forename: Yu-Tzu
authors.initials: YT
authors.lastname: Huang
authors.affiliation: World Premier International (WPI) Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Imura
authors.affiliation: World Premier International (WPI) Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Nemoto
authors.affiliation: Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
authors.forename: Chao-Hung
authors.initials: CH
authors.lastname: Cheng
authors.affiliation: World Premier International (WPI) Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan; Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan; Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Yamauchi
keywords: calcium D-gluconate; coprecipitation method; formation; hydroxyapatite; nanoparticles; potassium hydrogen phosphate; triblock copolymer F127