Single crystal growth of Pb5(PxAs1−xO4)3Cl solid solution with apatite type structure

Masaoka, Mikio; Kyono, Atsushi; Hatta, Toshihisa; Kimata, Mitsuyoshi

doi:10.1016/j.jcrysgro.2006.03.026

Cited by 16 publications

(19 citation statements)

References 23 publications

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“…In general, the aqueous concentrations of elements were strongly dependent on the mole fraction of the endmember 3 (OH) solid solution, the higher the solubility of the solid solution. In the present experiment, the dissolution occurred primarily within the first 480 h. After 480 h, the dissolution rate declined rapidly and a steady-state condition was achieved (Fig.…”

Section: Evolution Of Aqueous Compositionmentioning

confidence: 99%

“…[33] The Pure-phase equilibrium was assessed by calculating the saturation index (SI), defined by SI ¼ log IAP/K sp , where IAP is the ion activity product (i.e. [ ] 3 [OH À ]) and the solubility product K sp is the thermodynamic-equilibrium constant for the dissolution reaction. If the SI is equal to zero, the aqueous phase is in equilibrium with the solid phase.…”

Section: Saturation With Respect To Calcium Phosphates and Arsenatesmentioning

confidence: 99%

“…Calcium phosphate hydroxylapatite [Ca 5 (PO 4 ) 3 (OH)] is a naturally occurring material as a major component of animal bones and teeth. [1] On the industrial front it is being used as luminophosphors and as raw materials for the manufacture of several phosphatic fertilisers.…”

Section: Introductionmentioning

confidence: 99%

“…[1] On the industrial front it is being used as luminophosphors and as raw materials for the manufacture of several phosphatic fertilisers. [2,3] Hydroxylapatite shows a high capacity for substitutions of Ca and PO 4 3À by other cations and anions due to its crystal structure and chemical composition, [4] significant among which from the point of view of arsenic poisoning being the substitution of PO 4 3À by AsO 4 3À resulting in the formation of its isomorph, arsenate hydroxylapatite (AsHAP). [5][6][7] Arsenic toxicity is a global health problem affecting many millions of people.…”

Section: Introductionmentioning

confidence: 99%

“…[15] Some synthesis experiments at ambient temperatures were conducted to evaluate the conditions of formation and solubilities of different calcium arsenates. [11,16,17] Hydroxylapatite (HAP) is one of the most stable forms of calcium phosphate and exhibits a low solubility (K sp ¼ 10 À53.02 -10 À53.51 ); however, the solubility of AsHAP [Ca 5 (AsO 4 ) 3 (OH)] is significantly greater than that of HAP, [11,[18][19][20][21][22] which suggested that phosphate substitution in the arsenate compound could significantly reduce their solubilities. [21][22][23][24] The thermodynamic properties of solid solutions have a vital influence on the transport and fate of toxic metals in the environment.…”

Section: Introductionmentioning

confidence: 99%

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Dissolution and solubility of the arsenate - phosphate hydroxylapatite solid solution [Ca5(PxAs1 - xO4)3(OH)] at 25°C

et al. 2011

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Environmental context. Apatites form a large family of minerals and compounds that can incorporate a variety of ions, including arsenate that can substitute for phosphate. Apatites may therefore control the concentration of arsenic in some aqueous environments. This manuscript describes the synthesis and characterisation of the arsenate-phosphate hydroxylapatite solid solution and the solid solution-aqueous solution interaction.Abstract. Nine different members of the arsenate-phosphate hydroxylapatite solid solution [Ca 5 (P x As 1Àx O 4 ) 3 (OH)] were prepared and characterised by various techniques, and then dissolution of the synthetic solids was studied at 258C and pH 2 in a series of batch experiments. The concentrations of aqueous arsenate species increased rapidly at the beginning of the dissolution and reached a steady-state after 480 h. The concentrations of aqueous phosphate species increased very fast initially and reached a peak value within the first hour of dissolution and then declined slowly with time and remained constant after 240-360 h. The solubility of the Ca 5 (P x As 1Àx O 4 ) 3 (OH) solid solution increased and its stability decreased with an increase in the mole fraction of Ca 5 (AsO 4 ) 3 (OH). The dissolution followed or slightly overshot the Lippmann solutus curve, then approached the solutus curve. The Ca 5 (AsO 4 ) 3 (OH)-poor solid solution was in equilibrium with the arsenate-rich aqueous solution.

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Section: Evolution Of Aqueous Compositionmentioning

confidence: 99%

Section: Saturation With Respect To Calcium Phosphates and Arsenatesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Dissolution and solubility of the arsenate - phosphate hydroxylapatite solid solution [Ca5(PxAs1 - xO4)3(OH)] at 25°C

et al. 2011

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Synthesis and Characterization of Arsenate/Phosphate Fluorapatite Solid Solutions

Zhu

Chen

Long

et al. 2009

Metall Mater Trans A

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A series of arsenate-substituted fluorapatite (FA) was directly prepared through the aqueous precipitation method. Characterization studies from elemental analysis, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra, and scanning electron microscopy (SEM) have confirmed the formation of the arsenate/phosphate fluorapatite solid solutions (AsPFAs), i.e., Ca 5 (P x As 1-x O 4 ) 3 F, which had a single phase of apatite structure. The analysis of the measurements indicated that the unit cell a and c parameters did not vary smoothly with the degree of substitution, as expected by Vegard's law. The morphology was dependent of the arsenate/phosphate ratio. The solids with high As/(P + As) molar ratio of 0.29 to 1.0 were typically needlelike crystals, which developed along the c-axis; all apatites with the As/(P + As) molar ratio of <0.09 were large tabular. The phosphate peaks and the arsenate peaks in the FT-IR spectra were observed for the entire series of substituted apatites. The area of the phosphate peak was gradually suppressed and that of the arsenate peak increased as the proportion of the arsenate increased.

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Synthesis and characterization of arsenate/phosphate hydroxyapatite solid solution

et al. 2009

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Single crystal growth of Pb5(PxAs1−xO4)3Cl solid solution with apatite type structure

Cited by 16 publications

References 23 publications

Dissolution and solubility of the arsenate - phosphate hydroxylapatite solid solution [Ca5(PxAs1 - xO4)3(OH)] at 25°C

Dissolution and solubility of the arsenate - phosphate hydroxylapatite solid solution [Ca5(PxAs1 - xO4)3(OH)] at 25°C

Synthesis and Characterization of Arsenate/Phosphate Fluorapatite Solid Solutions

Synthesis and characterization of arsenate/phosphate hydroxyapatite solid solution

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