Effect of Anions on Morphology Control of Brushite Particles

Abstract:

Brushite (DCPD, CaHPO₄·2H₂O) crystals are of great significance in a range of fields including biology, medicine, chemistry, and materials science. One important issue is the control of their morphology; when the crystal growth conditions are changed, the morphology and surface crystal conditions also change. The chemical reaction behavior depends strongly on the surface condition of the particles. Here, we report the effect of coexisting anions on the morphology control of DCPD particles. We synthesized the particles through a liquid-phase reaction by mixing a starting solution of ammonium dihydrogen phosphate (NH₄H₂PO₄) and calcium salts. Calcium nitrate (Ca (NO₃)₂) and calcium acetate (Ca (CH₃COO)₂) were used as the calcium sources to clarify the pH dependence of the morphology. We mixed the solutions with the same pH values and agitated them, and observed the products by scanning electron microscopy (SEM) and X-ray diffraction (XRD); the DCPD morphology varies from petal-like to parallelogram structures depending on the initial pH value of the solution and the combination of the starting mixture. The effect of the acetic acid anion is to increase the driving force for the generation of DCPD crystal nuclei.

• Periodical: Key Engineering Materials (Volumes 529-530)
• Pages: 55-60
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.529-530.55
• Online since: November 2012
• Authors: Ryo Hamai, Takeshi Toshima, Masamoto Tafu, Takaaki Masutani, Tetsuji Chohji
• Keywords: Brushite, DCPD, Morpholoy, Solution-Phase Synthesis

References

[1] T. Lee and Y. C. Lin, Mimicking the initial development of calcium urolithiasis by screening calcium oxalate and calcium phosphate phases in various urine-like solutions, time points, and pH values at 37 °C, Cryst. Growth Des. 11 (2011) 2973-2992.

DOI: 10.1021/cg200246v

[2] S. Mandel and A. C. Tas, Brushite (CaHPO4·2H2O) to octacalcium phosphate (Ca8(HPO4)2(PO4)4·5H2O) transformation in DMEM solutions at 36. 5 °C, Mater. Sci. & Eng. C30 (2010) 245-254.

DOI: 10.1002/9781118095263.ch8

[3] O. Borkiewicz, J. Rakovan and C. L. Cahill, Time-resolved in situ studies of apatite formation in aqueous solutions, American Mineralogist, 95 (2010) 1224-1236.

DOI: 10.2138/am.2010.3168

[4] H. Ito, Y. Oaki and H. Imai, Selective synthesis of various nanoscale morphologies of hydroxyapatite via an intermediate phase, Cryst. Growth Des. 8 (2008) 1055-1059.

DOI: 10.1021/cg070443f

[5] H. Monma, T. Kamiya, Preparation of hydroxyapatite by the hydrolysis of brushite, J. Mat. Sci. 22 (1987) 4247-4250.

DOI: 10.1007/bf01132015

[6] A. C. Tas and S. B. Bhaduri, Chemical processing of CaHPO4·2H2O: Its conversion to hydroxyapatite, J. Am. Ceram. Soc. 87 (2004) 2195–220.

[7] J. A. Juhasz, S. M. Best, A. D. Auffret, W. Bonfield, Biological control of apatite growth in simulated body fluid and human blood serum, J Mater Sci: Mater. Med. 19 (2008) 1823–1829.

DOI: 10.1007/s10856-007-3344-7

[8] J. Gómez-Morales, J. M. Delgado-López, M. Iafisco, A. Hernández-Hernándezand María Prat, Amino acidic control of calcium phosphate precipitation by using the vapor diffusion method in microdroplets, Cryst. Growth Des. 11 (2011) 4802-4809.

DOI: 10.1021/cg2004547

[9] J. C. Elliott, Structure and chemistry of the apatites and other calcium orthophosphates. Elsevier, Amsterdam. (1994).