Nano-sized crystals of calcined hydroxyapatite (HAp) having spherical morphologies were fabricated by calcination at 800°for 1 h with an anti-sintering agent surrounding the original HAp particles and the agent was subsequently removed by washing after calcination. The original HAp particles were prepared by a modified emulsion system, and surrounded with poly(acrylic acid, calcium salt) (PAA-Ca) by utilizing a precipitation reaction between calcium hydroxide and poly(acrylic acid) adsorbed on the HAp particle surfaces in an aqueous medium. In the case of calcination without PAA-Ca, micron-sized particles consisting of sintered polycrystals were mainly observed by scanning electron microscopy, indicating the calcination-induced sintering among the crystals. On the other hand, most of the crystals calcined with the anti-sintering agent were observed as isolated particles, and the mean size of the HAp crystals was around 80 nm. This result indicates that PAA-Ca and its thermally decomposed product, CaO, surrounding the HAp crystals could protect them against calcination-induced sintering during calcination at 800°The HAp crystals calcined with PAA-Ca showed high crystallinity, and no other calcium phosphate phases could be detected.
|Number of pages||4|
|Journal||Journal of Nanoscience and Nanotechnology|
|Publication status||Published - Mar 1 2007|
ASJC Scopus subject areas
- Biomedical Engineering
- Materials Science(all)
- Condensed Matter Physics