title: Effect of ammonium carbonate on formation of calcium-deficient hydroxyapatite through double-step hydrothermal processing.
abstract: Double-step hydrothermal processing is a process where powder compacts of calcium phosphates are exposed to vapor of solvent solution, followed by being immersed in the solution. In the present study, we investigated the effects of ammonium carbonate on formation of calcium-deficient hydroxyapatite (CDHA) through double-step hydrothermal processing. The synthesized CDHA has high crystallinity when the solution has relatively low concentration of the ammonium carbonate ranging from 0.01 to 0.25 mol dm(-3). Carbonate content in the prepared samples were distinctly increased with increasing the concentration of ammonium carbonate to indicate formation of carbonate-containing calcium-deficient hydroxyapatite (CHAp) with low crystallinity. Morphology of the CHAp formed on the compacts varied progressively from rods and rosette-like shape to irregular shape with increase in the initial concentration of the ammonium carbonate in the solution. Application of ammonium carbonate in the double-step hydrothermal processing allows fabrication of irregular-shaped CDHA containing carbonate ions in both phosphate and hydroxide site, with low crystallinity, when the initial concentration of ammonium carbonate was 0.5 mol dm(-3) and more.
authors.affiliation: Graduate School of Engineering, Nagoya University, B2-3(611), Furo-cho, Chikusa-ku, Nagoya, 464-8603, Japan, prakashparthiban@gmail.com
authors.forename: S Prakash
authors.initials: SP
authors.lastname: Parthiban
authors.forename: Ill Yong
authors.initials: IY
authors.lastname: Kim
authors.forename: Koichi
authors.initials: K
authors.lastname: Kikuta
authors.forename: Chikara
authors.initials: C
authors.lastname: Ohtsuki
mesh_terms: D002118:Calcium / Q000737:chemistry*; D002254:Carbonates / Q000737:chemistry; D003460:Crystallization; D017886:Durapatite / Q000737:chemistry*; D004867:Equipment Design; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides / Q000737:chemistry; D007477:Ions; D008422:Materials Testing; D008956:Models, Chemical; D010710:Phosphates / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013054:Spectrophotometry, Atomic / Q000379:methods; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D002254:Carbonates; D006878:Hydroxides; D007477:Ions; D010710:Phosphates; D000644:Quaternary Ammonium Compounds; D017886:Durapatite; C040502:ammonium carbonate; D002118:Calcium