High-strength nanograined and translucent hydroxyapatite monoliths via continuous hydrothermal synthesis and optimized spark plasma sintering.
The synthesis of high-strength, completely dense nanograined hydroxyapatite (bioceramic) monoliths is a challenge as high temperatures or long sintering times are often required. In this study, nanorods of hydroxyapatite (HA) and calcium-deficient HA (made using a novel continuous hydrothermal flow synthesis method) were consolidated using spark plasma sintering (SPS) up to full theoretical density in ∼5 min at temperatures up to 1000°C. After significant optimization of the SPS heating and loading cycles, fully dense HA discs were obtained which were translucent, suggesting very high densities. Significantly high three-point flexural strength values for such materials (up to 158 MPa) were measured. Freeze-fracturing of disks followed by scanning electron microscopy investigation revealed selected samples possessed sub-200 nm sized grains and no visible pores, suggesting they were fully dense.
Chaudhry
Aqif A
AA
Clean Materials Technology Group, Department of Chemistry, University College London, Christopher Ingold Laboratories, 20 Gordon Street, London WC1H 0AJ, UK. aqifanwar@gmail.com
Yan
Haixue
H
Gong
Kenan
K
Inam
Fawad
F
Viola
Giuseppe
G
Reece
Mike J
MJ
Goodall
Josephine B M
JB
ur Rehman
Ihtesham
I
McNeil-Watson
Fraser K
FK
Corbett
Jason C W
JC
Knowles
Jonathan C
JC
Darr
Jawwad A
JA
D006882:Hydroxyapatites / Q000737:chemistry*; D008027:Light; D008422:Materials Testing / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D058626:Plasma Gases / Q000737:chemistry*; D012542:Scattering, Radiation; D013696:Temperature; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
D006882:Hydroxyapatites; D058626:Plasma Gases; D014867:Water