Influence of apatite seeds on the synthesis of calcium phosphate cement.
This preliminary study explores the seeding effect (using crystalline hydroxyapatite particles) on the setting time, compressive strength, phase evolution, and microstructure of calcium phosphate cements (CPC) based on monocalcium phosphate monohydrate and calcium hydroxide. Experimental results showed that the setting time varies from 5 to about 30 min, as the seed concentration increased from 0 to 20 wt%. The compressive strength of CPC increased from 4 to 17 MPa, followed by decrease to 12 MPa, for the same range of seeds content. The CPC transformed to predominantly apatitic structure within 24 h for all the samples, with or without the seeds. However, increase of the seed concentration improved the final crystallinity of the apatite phase, suggesting nucleation and growth effects during precipitation of CPC from the precursor solution. The microstructure of the resulting apatitic cement showed a change from essentially featureless (or glass-like) to thin, elongated plate-like morphology, as seeds concentration increased. Correlation between microstructural evolution and corresponding compressive strength of seeded CPC is investigated.
Yang
Quanzu
Q
Department of Metals and Materials Engineering, The University of British Columbia, Vancouver, Canada. quanzu@interchange.ubc.ca
Troczynski
Tom
T
Liu
Dean-Mo
DM
D001031:Apatites / Q000494:pharmacology*; D001843:Bone Cements; D002126:Calcium Hydroxide; D002130:Calcium Phosphates / Q000737:chemistry*; D019245:Compressive Strength; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors
D001031:Apatites; D001843:Bone Cements; D002130:Calcium Phosphates; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous; D002126:Calcium Hydroxide