Biomedical Engineering Reference
In-Depth Information
The XRD patterns of the β-TCP were sintered at various temperatures (1100°C, 1300°C and
1400°C) with different percentages of Fap (13.26 wt % and 40 wt %) were shown in Fig. 4.
These spectra are identical to the initial powder (β-TCP and Fap). We conclude that β-TCP
and the Fap were steady during the sintering process. But when left at 1300°C, the
thermogrammes indicate the germination of α-TCP phase. This phase is a proof of the
fragility of samples because the absolute densities of β-TCP and α-TCP were different.
Besides, the incorporation of Fap in tricalcium phosphate does not seem to be in its right
decomposition. Indeed, the XRD revealed only phases of departure (β-TCP and Fap) and α-
TCP.
The Nuclear magnetic resonance chemical shift spectra of the
31
P of the β-TCP as sintered at
various temperatures (1100°C; 1300°C and 1400°C) with different percentages of Fap (13.26
wt %; 33.16 wt % and 40 wt %) are shown in Fig. 5. The
31
P MAS-NMR solid spectra of
composites show the presence of three tetrahedral environments of the phosphorus. Indeed,
the
31
P MAS - NMR analysis reveals the presence of three tetrahedral P sites for the β-TCP
whereas the Fap possesses only one. This was similar to the result previously reported by
(Yashima et al., 2003). They show that the phosphorus of tricalcium phosphate is located in
three crystallographic sites: P(1)O
4
, P(2)O
4
, P(3)O
4
(Yashima et al., 2003). There is no record
of any phase modification of the β-TCP or Fap, which confirms that the two powders, β-TCP
and Fap were thermally steady between 1100°C and 1450°C.
β
f
β
(f)
f
β
f
β
f
β
f
β
β
f
β
α
β
f
β
α
f
β
β
β
β
f
β
f
f
f
(e)
β
β
β
f
β
β
f
α
β
f
β
f
β
β
β
β
β
f
f
f
f
β
(d)
β
β
β
f
β
f
β
f
f
f
β
β
β
β
β
α
β
β
β
(c)
β
β
f
f
f
β
f
β
β
f
β
α
f
β
f
f
β
β
β
β
β
β
β
β
f
(b)
f
f
β
f
β
β
f
β
β
f
f
f
f
β
β
β
β
f
β
β
β
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f
(a)
f
β
β
f
β
f
β
f
β
f
β
f
β
f
β
f
β
β
25
30
35
40
2θ (degrees)
Fig. 4. XRD patterns of β-TCP-Fap composites sintered for one hour at various temperatures
with different wt % of Fap: (a) 13.26 wt %, 1100°C; (b) 13.26 wt %, 1300°C; (c) 13.26 wt %,
1400°C; (d) 40 wt %, 1100°C; (e) 40 wt %, 1300°C and (f) 40 wt %, 1400°C (β : β-TCP; f: Fap; α
: α-TCP).
