Particle formation of hydroxyapatite precursor containing two components in a spray pyrolysis process

Abstract

The particle formation mechanism of hydroxyapatite precursor containing two components, Ca(OOCCH₃)₂ and (NH₄)₂HPO₄ with a ratio of Ca/P= 1.67, in a spray pyrolysis process has been studied by computational fluid dynamics (CFD) simulation on the transfer of heat and mass from droplets to the surrounding media. The focus included the evaporation of the solvent in the droplets, a second evaporation due to crust formation, the decomposition reaction of each component of the precursor, and a solid-state reaction that included the kinetic parameters of the precursor regarding its two components that formed the hydroxyapatite product. The rate of evaporation and the reacted fraction of the precursor both increased with temperature. The predicted average size of the hydroxyapatite particles agreed well with the experimental results. Therefore, the selected models were also suitable for predicting the average size of particles that contain two components in the precursor solution.

Keywords

droplet / hydroxyapatite particle / CFD / tubular furnace / spray pyrolysis

References

[1] Ortega J, Kodas T T. Control of particle morphology during multicomponent metal oxide powder generation by spray pyrolysis. Journal of Aerosol Science, 1992, 23(Suppl. 1): S253-S256

[2] Okuyama K, Lenggoro I W. Preparation of nanoparticles via spray route. Chemical Engineering Science, 2003, 58(3-6): 537-547

[3] Jain S, Skamser D J, Kodas T T. Morphology of single-component particles produced by spray pyrolysis. Aerosol Science and Technology, 1997, 27(5): 575-590

[4] Reuge N, Caussat B, Joffin N, Dexpert-ghys J, Verelst M, Dexpert H. Modeling of spray pyrolysis— why are the synthesized Y₂O₃ microparticles hollow? AIChE Journal. American Institute of Chemical Engineers, 2008, 54(2): 394-405

[5] Gurav A, Kodas T T, Pluym T, Xiong Y. Aerosol processing of materials. Aerosol Science and Technology, 1993, 19(4): 411-452

[6] Jayanthi G V, Zhang S C, Messing G L. Modeling of solid particle formation during solution aerosol thermolysis. Aerosol Science and Technology, 1993, 19(4): 478-490

[7] Reuge N, Caussat B. A dimensionless study of the evaporation and drying stages in spray pyrolysis. Computers & Chemical Engineering, 2007, 31(9): 1088-1099

[8] Widiyastuti W, Wang W N, Lenggoro I W, Iskandar F, Okuyama K. Simulation and experimental study of spray pyrolysis of polydispersed droplets. Journal of Materials Research, 2007, 22(7): 1888-1898

[9] Handscomb C, Kraft M, Bayly A. A new model for the drying of droplets containing suspended solids after shell formation. Chemical Engineering Science, 2009, 64(2): 228-246

[10] Zhou H, Lee J. Nanoscale hydroxyapatite particles for bone tissue engineering. Acta Biomaterialia, 2011, 7(7): 2769-2781

[11] Zhang L, Webster T J. Nanotechnology and nanomaterials: Promises for improved tissue regeneration. Nano Today, 2009, 4(1): 66-80

[12] Cho J S, Rhee S H. Formation mechanism of nano-sized hydroxyapatite powders through spray pyrolysis of calcium phosphate solution containing polyethylene glycol. Journal of the European Ceramic Society, 2013, 33(2): 233-241

[13] An G H, Wang H J, Kim B H, Jeong Y G, Choa Y H. An G H, Wang H J, Kim B H, Jeong Y G, Choa Y H. Fabrication and characterization of a hydroxyapatite nanopowder by ultrasonic spray pyrolysis with salt-assisted decomposition. Materials Science and Engineering A, 2007, 449-451: 821-824

[14] Itatani K, Abe M, Umeda T, Davies I J, Koda S. Morphological and microstructural changes during the heating of spherical calcium orthophosphate agglomerates prepared by spray pyrolysis. China Particuology, 2004, 2(5): 200-206

[15] Trommer R M, Santos L A, Bergmann C P. Nanostructured hydroxyapatite powders produced by a flame-based technique. Materials Science and Engineering C, 2009, 29(6): 1770-1775

[16] Rajan R, Pandit A. Correlation to predict droplet size in ultrasonic atomization. Ultrasonics, 2001, 39(4): 235-255

[17] Ansys Inc. Ansys Fluent 13.0 Theory Guide. USA, 2010

[18] Luijten C, Bosschaart K, Van Dongen M. A new method for determining binary diffusion coefficients in dilute condensable vapors. International Journal of Heat and Mass Transfer, 1997, 40(15): 3497-3502

[19] Poling B E, Prausnitz J M, O'Connel J P. The Properties of Gas and Liquids. New York: Mc. Graw-Hill Inc., 2001

[20] Nešić S, Vodnik J. Kinetics of droplet evaporation. Chemical Engineering Science, 1991, 46(2): 527-537

[21] Jalota S, Tas A C, Bhaduri S B. Synthesis of HA-seeded TTCP (Ca₄(PO₄)₂O) powders at 1230 °C from Ca(CH₃COO)₂.H₂O and NH₄H₂PO₄. Journal of the American Ceramic Society, 2005, 88(12): 3353-3360

[22] Kissinger H E. Reaction kinetics in differential thermal analysis. Analytical Chemistry, 1957, 29(11): 1702-1706

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