Hydroxyapatite nanopowders were synthesized by a sol–gel emulsion technique by varying the
concentration of a non-ionic surfactant in the organic phases (oil phase) of water-in-oil (w/o) emulsion. Calcium acetate dissolved in distilled water and phosphorous pentoxide dissolved in 2-butanol were used as starting precursors. The prepared sol was emulsified in a support solvent (cyclohexane) containing 2, 4 and 5
volume% of surfactant (Span 80), followed by the addition of triethylamine, for gelation. The gel powders
thus obtained were calcined at different temperatures up to 750°C. Characterization was done using XRD,
SEM and TEM. Pellets were made from the developed HAP powders and tested for its biocompatibility after
their immersion in the simulated body fluid.