Kollagenosen

Synthesis of Nanocrystalline Hydroxyapatite Nanorods via Hydrothermal Conditions

“…The shape of the t 3 and the absence of the C-O absorption bands at 710 cm -1 indicate that no calcite was associated with the HAp. Carbonate ions can substitute for either OHor PO 4 3ions in the apatite structure (type A CO 3 2- or type B CO 3 2-) [24,25]. The FTIR results further confirm that the as-synthesized powders are pure HAp.…”

Space group and lattice constants of Ca10(PO4)6CO3

“…Carbonate apatite was prepared as previously described (Bonel, 1972). X-ray diffraction powder patterns were made with a Guinier camera using Co K:~ radiation, and using Cu Kc~ radiation (2= 1-5419 A) with a 90 mm cylindrical toroidal focusing camera (Elliott, 1965) and a diffractometer with graphite monochromator with step scanning, typically 3000 s per 0.05 ° 20 step size, 1 ° divergence and 0.2 mm receiving slits.…”

“…Furthermore, if the percentage replacement was greater than 90%, the presence of splitting of some lines in the X-ray diffraction pattern showed that the symmetry of the lattice had been lowered. A similar but more marked lowering of the symmetry occurs in Sr10(PO4)6CO3, for which the diffraction pattern has been indexed on the basis of a doubled unit cell with monoclinic space group P21/b and lattice constants a = 9.88 (2), b = 19.72 (5), c= 7.23 (9) A and 7= 119.4 (3) ° (Nadal, Legros, Bonel & Montel, 1971;Bonel, 1972).…”

“…The X-ray diffraction powder pattern after the reaction showed that the hexagonal unit cell of the apatite had changed from a=9-421, c=6.88 A for hydroxyapatite, to approximately a =9.54 and c= 6.87 A. Subsequently, it was found (Bonel, 1972) that if very dry CO2 and stoichiometric hydroxyapatite were used, it was possible to obtain nearly total replacement of the hydroxyl groups by carbonate groups. Furthermore, if the percentage replacement was greater than 90%, the presence of splitting of some lines in the X-ray diffraction pattern showed that the symmetry of the lattice had been lowered.…”