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Long and short range order structural analysis of In-situ formed biphasic calcium phosphates.

Kim DH, Hwang KH, Lee JD, Park HC, Yoon SY - Biomater Res (2015)

Bottom Line: In this study, BCP were prepared by aqueous co-precipitation and calcination method.The refined structural parameters of in-situ formed BCP confirmed that all the investigated structures have crystallized in the corresponding hexagonal (space group P63/m) and rhombohedral (space group R3c) structures.The significant short range order structural change of BCP was determined by Raman analysis.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Engineering, Pusan National University, Busan, 609-735 Republic of Korea.

ABSTRACT

Background: Biphasic calcium phosphates (BCP) have attracted considerable attention as a bone graft substitute. In this study, BCP were prepared by aqueous co-precipitation and calcination method. The crystal phases of in-situ formed BCP consisting of hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP) were controlled by the degree of calcium deficiency of precursors. The long and short range order structures of biphasic mixtures was investigated using Rietveld refinement technique and high resolution Raman spectroscopy. The refined structural parameters of in-situ formed BCP confirmed that all the investigated structures have crystallized in the corresponding hexagonal (space group P63/m) and rhombohedral (space group R3c) structures.

Results: The crystal phases, Ca/P molar ratio, and lattice parameters of in-situ formed BCP consisting of HAp and β-TCP were controlled by the degree of calcium deficiency of calcium phosphate precursors. The significant short range order structural change of BCP was determined by Raman analysis.

Conclusions: The long and short range order structural changes of in-situ formed BCP might be due to the coexistence of β-TCP and HAp crystal phases.

No MeSH data available.


Related in: MedlinePlus

a XRD patterns, b axial ratio, and c volumetric expansion behavior of unit cells of in-situ formed BCP. (Note: axis of β-TCP and HAp is a = b and axial angle is α = β = 90°, γ = 120°)
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Fig2: a XRD patterns, b axial ratio, and c volumetric expansion behavior of unit cells of in-situ formed BCP. (Note: axis of β-TCP and HAp is a = b and axial angle is α = β = 90°, γ = 120°)

Mentions: Figure 2 shows biphasic behaviors and effects of crystal system of in situ formed BCP with different phase contents. The expanded XRD patterns of BCP in the close scan around the main peak region (2θ = 30-35°) as shown in Fig. 2(a). The β-TCP (0210) peak is well distinguished and differentiated from the HAp (211) peak. Figure 2(b) shows axis ratio of β-TCP and HAp phase in the lattice parameters of in-situ formed BCP with different phase contents. In the case of in-situ formed BCP, the as-calculated c/a axis ratio of β-TCP phase was increased with increasing HAp phase contents as shown in Fig. 2(b). On the other hand, the a/c axis ratio of HAp showed a little decrease to closed a/c ratio of monophasic HAp. In contrast to result of β-TCP, the as-calculated a/c axis ratio of HAp phase of in-situ formed BCP was decreased to the theoretical a/c axis ratio (a/c ratio = 1.3689, ICSD # 87670). In addition, a volume for unit cell of in-situ formed BCP showed the volumetric expansion, compared to the monophasic HAp and β-TCP, as shown in Fig. 2(c).Fig. 2


Long and short range order structural analysis of In-situ formed biphasic calcium phosphates.

Kim DH, Hwang KH, Lee JD, Park HC, Yoon SY - Biomater Res (2015)

a XRD patterns, b axial ratio, and c volumetric expansion behavior of unit cells of in-situ formed BCP. (Note: axis of β-TCP and HAp is a = b and axial angle is α = β = 90°, γ = 120°)
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4697325&req=5

Fig2: a XRD patterns, b axial ratio, and c volumetric expansion behavior of unit cells of in-situ formed BCP. (Note: axis of β-TCP and HAp is a = b and axial angle is α = β = 90°, γ = 120°)
Mentions: Figure 2 shows biphasic behaviors and effects of crystal system of in situ formed BCP with different phase contents. The expanded XRD patterns of BCP in the close scan around the main peak region (2θ = 30-35°) as shown in Fig. 2(a). The β-TCP (0210) peak is well distinguished and differentiated from the HAp (211) peak. Figure 2(b) shows axis ratio of β-TCP and HAp phase in the lattice parameters of in-situ formed BCP with different phase contents. In the case of in-situ formed BCP, the as-calculated c/a axis ratio of β-TCP phase was increased with increasing HAp phase contents as shown in Fig. 2(b). On the other hand, the a/c axis ratio of HAp showed a little decrease to closed a/c ratio of monophasic HAp. In contrast to result of β-TCP, the as-calculated a/c axis ratio of HAp phase of in-situ formed BCP was decreased to the theoretical a/c axis ratio (a/c ratio = 1.3689, ICSD # 87670). In addition, a volume for unit cell of in-situ formed BCP showed the volumetric expansion, compared to the monophasic HAp and β-TCP, as shown in Fig. 2(c).Fig. 2

Bottom Line: In this study, BCP were prepared by aqueous co-precipitation and calcination method.The refined structural parameters of in-situ formed BCP confirmed that all the investigated structures have crystallized in the corresponding hexagonal (space group P63/m) and rhombohedral (space group R3c) structures.The significant short range order structural change of BCP was determined by Raman analysis.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Engineering, Pusan National University, Busan, 609-735 Republic of Korea.

ABSTRACT

Background: Biphasic calcium phosphates (BCP) have attracted considerable attention as a bone graft substitute. In this study, BCP were prepared by aqueous co-precipitation and calcination method. The crystal phases of in-situ formed BCP consisting of hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP) were controlled by the degree of calcium deficiency of precursors. The long and short range order structures of biphasic mixtures was investigated using Rietveld refinement technique and high resolution Raman spectroscopy. The refined structural parameters of in-situ formed BCP confirmed that all the investigated structures have crystallized in the corresponding hexagonal (space group P63/m) and rhombohedral (space group R3c) structures.

Results: The crystal phases, Ca/P molar ratio, and lattice parameters of in-situ formed BCP consisting of HAp and β-TCP were controlled by the degree of calcium deficiency of calcium phosphate precursors. The significant short range order structural change of BCP was determined by Raman analysis.

Conclusions: The long and short range order structural changes of in-situ formed BCP might be due to the coexistence of β-TCP and HAp crystal phases.

No MeSH data available.


Related in: MedlinePlus