Calcium phosphate apatites with variable Ca/P atomic ratio I. Synthesis, characterisation and thermal stability of powders

Raynaud, Sylvie; Champion, Éric; Bernache‐Assollant, Didier; Thomas, Philippe

doi:10.1016/s0142-9612(01)00218-6

Cited by 700 publications

(477 citation statements)

References 16 publications

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“…The final step of the chemical assessment was performed using ICP to quantify the Ca:P molar ratio ( Table 2). The theoretical Ca:P ratio for pure HA, β-TCP and calcium pyrophosphate are 1.67, 1.5 and 1, respectively [25]. The samples with calcination temperature of 800 ℃ had a Ca:P ratio of ~1.43, while at 975 ℃ the ratio was lower at ~1.37.…”

Section: Discussion/conclusionmentioning

confidence: 97%

Sintering effects on chemical and physical properties of bioactive ceramics

et al. 2013

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Abstract:The objective of this study was to characterize the chemical and physical properties of bioactive ceramics prepared from an aqueous paste containing hydroxyapatite (HA) and beta tri-calcium phosphate (β-TCP). Prior to formulating the paste, HA and β-TCP were calcined at 800 ℃ and 975 ℃ (11 h), milled, and blended into 15%/85% HA/β-TCP volume-mixed paste. Fabricated cylindrical rods were subsequently sintered to 900 ℃, 1100 ℃ or 1250 ℃. The sintered specimens were characterized by helium pycnometry, X-ray diffraction (XRD), Fourier transform-infrared (FT-IR), and inductively coupled plasma (ICP) spectroscopy for evaluation of porosity, crystalline phase, functional-groups, and Ca:P ratio, respectively. Mechanical properties were assessed via 3-point bending and diametral compression. Qualitative microstructural evaluation using scanning electron microscopy (SEM) showed larger pores and a broader pore size distribution (PSD) for materials sintered at 900 ℃ and 1100 ℃, whereas the 1250 ℃ samples showed more uniform PSD. Porosity quantification showed significantly higher porosity for materials sintered to 900 ℃ and 1250 ℃ (p < 0.05). XRD indicated substantial deviations from the 15%/85% HA/β-TCP formulation following sintering where lower amounts of HA were observed when sintering temperature was increased. Mechanical testing demonstrated significant differences between calcination temperatures and different sintering regimes (p < 0.05). Variation in chemical composition and mechanical properties of bioactive ceramics were direct consequences of calcination and sintering.

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Section: Discussion/conclusionmentioning

confidence: 97%

Sintering effects on chemical and physical properties of bioactive ceramics

et al. 2013

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“…The observation of the ν3 symmetric P-O stretching vibration at 1058 and 1051 cm-1 for cHA and bHA as a distinguishable peak, together with the bands 572/603 cm-1 & 570/603 cm-1 corresponding to ν4 bending vibration indicates. [25][26][27] Different types of chemical bonds which are present in various components of bone at given infrared absorption bands. Changes in the environment of molecules cause shifts in the intensities and positions of their corresponding absorption bands.…”

Section: Ftir Analysismentioning

confidence: 99%

Extraction of Hydroxyapatite from Bovine and Human Cortical Bone by Thermal Decomposition and Effect of Gamma Radiation: A Comparative Study

Asaduzzaman¹

2017

IJCAM

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Hydroxyapatite (HA) was extracted from bovine and human cortical bone by thermal decomposition process and was characterized using several analytical tools, including thermo-gravimetric analysis (TGA), X-ray diffraction analysis (XRD), X-ray fluorescence analysis (XRF), Flourier transformed infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Removal of organic matter from the bone was confirmed by TGA. XRD data confirmed that HA was the only crystalline phase when sintered at 950 °C. XRF analysis revealed that calcium and phosphorus were the main components and magnesium, sodium were the minor elements in which some trace elements (iron, potassium and zinc) were also present. FT-IR spectra of HA confirmed the presence of a carbonated group and the similarities to commercial HA. When HA were irradiated at 25kGy, there was no significant change of their properties. In vitro cytotoxicity of the HA powder were also evaluated and the samples showed no cytotoxic effect. These results suggested that HA derived from bovine and human bone by thermal decomposition has the potential to be used in bone tissue engineering.

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“…Hydroxyapatite, HA (Ca 10 (PO 4 ) 6 (OH) 2 ), is an inorganic, insoluble salt [1]. It belongs to a family of calcium phosphates (CaPO 4 ) and is one of the most stable crystal structures of the CaPO 4 [2].…”

Section: Introductionmentioning

confidence: 99%

“…It belongs to a family of calcium phosphates (CaPO 4 ) and is one of the most stable crystal structures of the CaPO 4 [2]. This inorganic salt has a similar chemical composition to that of human bones and teeth [3], and may consequently serve as a useful coating for human implantations and dental affixtures [4].…”

Section: Introductionmentioning

confidence: 99%