Si-substituted hydroxyapatite nanopowders: Synthesis, thermal stability and sinterability

Journal Article · Wed Feb 04 04:00:00 EST 2009 · Materials Research Bulletin

DOI:https://doi.org/10.1016/j.materresbull.2008.05.013· OSTI ID:21199672

Bianco, Alessandra ^[1]; Cacciotti, Ilaria ^[1]; Lombardi, Mariangela ^[2]; Montanaro, Laura ^[2]

---

1. University of Rome Tor Vergata, Department of Chemical Sciences and Technologies, INSTM Research Unit Tor Vergata, Via della Ricerca Scientifica 1, 00133 Roma (Italy)
2. Politecnico of Torino, Department of Materials Science and Chemical Engineering, INSTM Research Unit Politecnico di Torino: LINCE Lab, Corso Duca degli Abruzzi, 24-10129 Torino (Italy)

Synthetic hydroxyapatites incorporating small amounts of Si have shown improved biological performances in terms of enhanced bone apposition, bone in-growth and cell-mediated degradation. This paper reports a systematic investigation on Si-substituted hydroxyapatite (Si 1.40 wt%) nanopowders produced following two different conventional wet methodologies: (a) precipitation of Ca(NO{sub 3}){sub 2}.4H{sub 2}O and (b) titration of Ca(OH){sub 2}. The influence of the synthesis process on composition, thermal behaviour and sinterability of the resulting nanopowders is studied. Samples were characterised by electron microscopy, induced coupled plasma atomic emission spectroscopy, thermal analysis, infrared spectroscopy, N{sub 2} adsorption measurements, X-ray diffraction and dilatometry. Semicrystalline Si-substituted hydroxyapatite powders made up of needle-like nanoparticles were obtained, the specific surface area ranged between 84 and 110 m{sup 2}/g. Pure and Si-substituted hydroxyapatite nanopowders derived from Ca(NO{sub 3}){sub 2}.4H{sub 2}O decomposed around 1000 deg. C. Si-substituted hydroxyapatite nanopowders obtained from Ca(OH){sub 2} were thermally stable up to 1200 deg. C and showed a distinct decreased thermal stability with respect to the homologous pure sample. Si-substituted hydroxyapatites exhibited higher sintering temperature and increased total shrinkage with respect to pure powders. Nanostructured dense ceramics were obtained by sintering at 1100 deg. C Si-substituted hydroxyapatites derived from Ca(OH){sub 2}.

• OSTI ID: 21199672
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 2 Vol. 44; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
ADSORPTION
APATITES
BEHAVIOR
CALCIUM HYDROXIDES
CALCIUM NITRATES
CERAMICS
DILATOMETRY
ELECTRON MICROSCOPY
EMISSION SPECTROSCOPY
INFRARED SPECTRA
NANOSTRUCTURES
PHASE TRANSFORMATIONS
SINTERING
SPECIFIC SURFACE AREA
STABILITY
SYNTHESIS
TEMPERATURE RANGE 1000-4000 K
TITRATION
X-RAY DIFFRACTION