Innovative Preparation Calcium Hydroxyapatite from

Applied Mechanics and Materials ISSN: 1662-7482, Vol. 851, pp 8-13 doi:10.4028/www.scientific.net/AMM.851.8 © 2016 Trans Tech Publications, Switzerland

Submitted: 2016-03-29 Revised: 2016-06-20 Accepted: 2016-06-29 Online: 2016-08-12

Innovative Preparation Calcium Hydroxyapatite from Duck Eggshell via Pyrolysis Nuchnapa Tangboriboon1,a* and Jularpar Suttiprapar 2,b 1,2

Materials Engineering Department, Faculty of Engineering, Kasetsart University, Bangkok 10900, Thailand a*

[email protected] [email protected]

Keywords: Hydroxyapatite, Phase transformation, Duck eggshell, Biomaterial

Abstract. Calcium hydroxyapatite made from duck eggshell react to phosphoric acid with the Ca/P mole ratio 1.67 and calcined at 800º, 900º, and 1000ºC for each temperature 2 hr. Duck eggshell is a source of calcium carbonate having high purity content more than 98.101 %w/w and small amount of other metal oxides. Duck eggshell is a bio-material similar to other calcium sources i.e. coral, animal bone, and seashell. There are many advantages of using duck eggshell as a raw material such as abundant, low price, high purity of calcium carbonate content, easy to calcium phosphate formation, biocompatibility, bioactive, non-toxic for human, and the high percentage of ceramic yield 69.73%w/w. In addition, one of the most important advantages is to reduce the amount of duck eggshell waste from household and food industries as environmental conservation. The optimum condition to obtain high purity hydroxyapatite is sintering calcium phosphate at 1000ºC for 2 hr. The average particle size, specific surface are, pore diameter, and true density of sample sintered at 1000ºC for 2 hr are 39.92 µm, 2.12 m2/g, 98.96 Å, 3.02 g/cm3, respectively, in soft fine white powder. Furthermore, the results obtained by XRF, SEM, and XRD confirmed of sample fired at 1000ºC for 2 hr to be calcium hydroxyapatite (HA, Ca10(PO4)6(OH)2) of Ca/P mole ratio 1.67 and small amount of calcium phosphate (β-TCP, Ca3PO4) of Ca/P mole ratio 1.5. Therefore, the duck eggshell is a potentially bio-ceramic material to prepare calcium hydroxyapatite applied for biomedical, bio-dental, and many industries i.e. pharmaceutical, toothpaste, cosmetic, and nutrient food etc. Introduction Calcium phosphates are a great interesting material known as a bio-ceramic which is a special significant for human bones, teeth, and skeletal tissues [1-4]. Since most of them are widely applied for implantation, replacement, and restoration in order to esthetic and functional uses. Calcium hydroxyapatite (HA, Ca10(PO4)6(OH)2) is one kind of calcium phosphate with the Ca/P mole ratio 1.67. There are many advantages i.e. biocompatibility, non-toxic, non-immunogenic agent, non-inflammatory, bioactive, chemical resistance, and good mechanical and physical properties. Calcium phosphates can be made from many kinds of biogenic materials such as seashell [5], eggshell [1, 3, 6-7], animal bone [8], and coral [9, 10]. Duck eggshell has a mineral composition similar to those of hen eggshell, animal bone, seashell and coral. The duck eggshell represents 11% w/w of the total weight approximately 74.9-78 g of a duck egg [11]. The chemical composition of duck eggshell composed of calcium carbonate 96.35%w/w, other oxide compounds of 0.61%w/w, and other organic matters of 3.04%w/w [11]. The Agricultural Statistics of Thailand reported the quantities of ducks’ eggs production approximately 1.5 x 109 eggs per year. Therefore, the duck eggshells waste is approximately 30 x 106 metric tons per year in Thailand. The duck eggshell utilization is to reduce waste problem in household, to reduce global climate warming, and to develop novelty of green ceramic materials and products. There are many methods to synthesis calcium hydroxyapatite and other calcium phosphates from eggshells i.e. hydrothermal process, sol-gel process, wet chemical precipitation, spray pyrolysis, and solid state reaction [3, 12]. The purpose of this study is to prepare calcium hydroxyapatite from duck eggshell react to phosphoric acid via pyrolysis at 800º, 900º, and 1000ºC for 2 hr. The obtained samples were characterized the physical-chemical properties, and microstructure by BET, particle size analyzer, XRD, and SEM, respectively. All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications, www.ttp.net. (#69219440-26/08/16,16:37:28)

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Experimental Materials and methods Duck eggshell was collected from local cafeteria in the university, Bangkok, Thailand. The raw duck eggshells were cleaned with tap water, dried in the air at room temperature (27ºC) for 2 days, and ground with a high speed mill for 120 min. Hydrophosphoric acid (H3PO4) was purchased from Arsom Co., Ltd., Thailand. Hydrophosphoric acid is high purity 85%, colorless, odorless, melting temperature 42.35ºC, and highly soluble in water and alcohol. Instruments Muffle furnace (Nebertherm, Ceramotherm with thermocouple type K, NiCr-Ni) was used to calcine the duck eggshells. The muffle furnace was used to calcine the precipitate calcium hydrogen phosphate powder prepared from the reaction between duck eggshell powder react to phosphoric acid at room temperature, and then calcined at each firing temperature 800°, 900°, and 1000°C for 2 hr, with a heating rate of 10ºC/min in order to comparison study the physical-chemical properties and microstructures. Rapid mill model RM 1105 with speed 500 rpm was supplied by Compound Clay Co., Ltd., Thailand. The rapid mill or ball mill made of porcelain pot and porcelain balls used for grinding the duck eggshell to get the fine powder. X-ray diffraction (XRD) was taken and analyzed using a Bruker AXS analyzer (D8 Discover) with VANTEC-1 Detector. Samples were analyzed using a double-crystal wide-angle goniometry. Scans were measured from 5°-80° 2θ at a scan speed of 5° 2θ/min in 0.05° or 0.03° 2θ increments using CuKα radiation (λ = 0.15406 nm). Peak positions were consistent with those of the International Center for Diffraction Data Standard (JCPDS) patterns to identify crystalline phases. X-ray fluorescence (XRF) was used to determine the chemical compositions: Philips, model PW 2400 was used with the tube current of 1000 mA and an acquisition lifetime of 30s. Scanning Electron Microscope (SEM) was taken and characterized using SEM, JEOL-5200. The duck eggshell powder and calcium hydrogen phosphate samples were mounted on a stub using carbon paste and were sputter-coated to ~0.1 µm of gold to improve conductivity. The acceleration voltages of 11-13 kV with magnifications of 1,000 and 5,000 times were used. Calcium Hydrogen Phosphate and Hydroxyapatite Powder Preparation The duck eggshell was ground for 120 min to fine powder which is the calcium carbonate compound (CaCO3) containing more than 98%wt. Calcium carbonate in duck eggshell can react to 85% phosphoric acid at room temperature (27ºC) with the weight ratio 10:6 to form the chemical reaction according to the equations as shown in (1) - (4) At room temperature (27ºC) or before firing: CaCO3 + 2 H3PO4 2 CaCO3 + 2 H3PO4

Ca(H2PO4)2.H2O+CO2 CaHPO4.2H2O+CaHPO4 + 2CO2

(1) (2)

Firing at 800º, 900º, and 1000ºC for 2 hr or after firing: 10 CaCO3 + 6 H3PO4 3 CaCO3 + 2 H3PO4

Ca10(PO4)6.(OH)2 + 10CO2 + 8H2O (3) Ca3(PO4)2 + 3CO2 + 3H2O (4)

When the chemical reaction between CaCO3 and H3PO4 occurred at room temperature (27ºC), the precipitated calcium hydrogen phosphate compounds: Ca(H2PO4)2.H2O called monocalcium phosphate monohydrate (MCPM) with Ca/P 0.5 and dicalcium phosphate anhydrous (DCPD) or brushite (CaHPO4.2H2O) with Ca/P 1.0. When the chemical reaction occurred, the CO2 was released as shown in the equations (1) and (2), respectively. Precipitated calcium hydrogen phosphate powder was filtered, rinsed with tap water 2-3 times, and dried in the oven at 110°C for 24 hr. After that, the dried calcium hydrogen phosphate compounds were calcined at 800°, 900°, and 1000°C at each firing

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temperature for 2 hr. Calcium hydrogen phosphate compounds converted to other forms of calcium hydrogen phosphate namely hydroxyapatite (HA), (Ca10(PO4)6.(OH)2) with Ca/P 1.67 and ß-tricalcium phosphate (ß-TCP), (Ca3(PO4)2) with Ca/P 1.5 as shown in the equations (3) and (4), respectively. The precipitated calcium hydrogen phosphate compounds before and after firing were characterized by XRF, SEM, XRD, particle size analyzer, BET, and pycnometer for true density measurement. Results and Discussion Characteristics and Physical Properties of Raw Materials and Calcium Hydrogen Phosphate Chemical composition of raw duck eggshell both of before and after firing measured by XRF at room temperature (27ºC) is tabulated in Table 1. The main composition of duck eggshell before firing is calcium carbonate (CaCO3) approximately 98.101%wt and the other oxide compounds 1.899 %wt i.e. Na2O, MgO, Al2O3, SiO2, etc. The calcined eggshell powder at 900ºC for 2 hr contains calcium oxide (CaO) 97.805%wt and the other oxide compounds 2.195%wt. Table 1 Chemical composition of duck eggshells before and after firing at 900ºC for 2 hr Duck eggshells Calcined eggshells Elements

Compounds

Na Mg Al Si P S Cl K Ca Cu Sr

Na2O MgO Al2O3 SiO2 P2O5 SO3 Cl K2O CaCO3 CuO SrO

Weight (%) 0.204 0.286 0.035 0.073 0.443 0.764 0.035 0.038 98.101 0.009 0.013

Elements

Compounds

Na Mg Si P S Cl K Ca Sr

Na2O MgO SiO2 P2O5 SO3 Cl K2O CaO SrO

Weight (%) 0.161 0.656 0.255 0.775 0.215 0.053 0.059 97.805 0.019

The raw duck eggshell powder in white color and little stench odor has avg. particle size, true density, specific surface area, and pore diameter equal to 41.10 µm. 2.25 g/cm3, 7.79 m2/g, and 17.69Å, respectively. While the calcium phosphate powder fired at 900º for 2 hr has the avg. particle size, true density, specific surface area, and pore diameter close to the data of hydroxyapatite powder fired at 1000ºC for 2 hr. However, the best condition to obtain high purity hydroxyapatite is firing temperature at 1000°C for 2 hr. The sample were fired at 1000ºC having the avg. particle size 39.92 µm, true density 3.02 g/cm3, specific surface area 2.12 m2/g, and pore diameter 98.96Å, respectively. The obtained true density of hydroxyapatite fired at 1000ºC 3.02 g/cm3 is closed to the theoretical density 3.08 g/cm3 measured by XRD consistent with the JCPDS no.01-074-0566. Both of the hydroxyapatite powder fired at 900º and 1000ºC has bright white color, soft, and fine powder without stench odor. Chemical compositions of calcium hydrogen phosphate powder before and after firing at 1000°C for 2 hr, measured by XRF are data tabulated in Table 2. Calcium oxide (CaO) and phosphorus oxide (P2O5) of raw duck eggshell before firing are 90.880 %wt and 9.120 %wt, respectively. While CaO and P2O5 content after firing are 91.920 %wt and 8.080 %wt, respectively. Therefore, duck eggshell is a potentially candidate acted as a raw material for purify hydroxyapatite preparation.


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Table 2 Chemical composition of calcium hydrogen phosphate powder before and after firing at 1000°C for 2 hr, measured by XRF Weight of calcium Weight of calcium Elements Weight Compounds phosphate phosphate (%) before firing after firing at 1000°C (wt%) (wt%) P 3.979 P2O5 9.120 8.080 Ca 64.952 CaO 90.880 91.920 O 31.096 XRD peak patterns of raw duck eggshell before and after calcination at 900°C for 2 hr, dried calcium hydrogen phosphate before firing, and calcium hydrogen phosphate powder after firing at 800°, 900°, and 1000°C, each temperature for 2 hr measured at 27ºC in the range of 5º-80º are shown in Fig. 1. The XRD peak patterns of raw duck eggshell is consistent with the JCPDS no. 01-086-2339 calcite or rhombohedral phase of 2Ɵ:I/Io(%) i.e. 23.08°:9%, 29.46°:100%, 35.93°:11%, 39.47°:16%, 43.17°:15%, 47.55°:21%, and 48.57°:20% [12]. The XRD peak pattern of raw duck eggshell calcined at 900ºC for 2 hr to form CaO powder indicates a crystalline phase of the lime face-centered cubic phase formation (Fm3m) which corresponding to CaO and consistent with JCPDS no. 00-037-1497. The XRD peak pattern of calcium hydrogen phosphate before firing shows crystalline phase formation of hydroxyapatite (HA) and mixture of other calcium-based chemical species such as CaO, CaCO3, and carbonate apatite consistent with the JCPDS file nos. of 00-083-1762 (CaCO3, rhombohedral), 01-002-1350 (calcium hydrogen phosphate, CaHPO4), and 00-002-0085 (brushite, CaH5PO6). When the calcium hydrogen phosphate was fired at 800ºC, the XRD peak patterns shows apparently the crystalline phase formation associated with calcium phosphate, calcium hydrogen phosphate and small amount of hydroxyapatite (HA) consistent with the JCPDS file nos. of 01-070-2065 (Ca3(PO4)2, rhombohedral at 2Ɵ: 31.023°:100%, 34.335°: 70.3%, and 27.777°: 56%), 00-002-1350 (CaHPO4 at 2Ɵ: 53.212°:100%, 49.498°:70%, and 26.668°:90%), and 01-074-0366 (Ca10(PO4)6(OH)2, hexagonal at 2Ɵ:31.766°:100%, 32.897°:61.3%, and 32.195°:51.5%), respectively. The XRD pattern of calcium phosphate sample calcined at 900ºC shows mixed crystalline phase formation of hydroxyapatite, calcium phosphate, and calcia consistent with the JCPDS nos.01-074-0566, 01-070-2065, and 00-037-1497, respectively. While the XRD pattern of calcium phosphate sample sintered at 1000ºC shows high purity hydroxyapatite mixed with small amount of β-calcium phosphate consistent with the JCPDS no.01-070-2065 of β-Ca3(PO4)2 rhombohedral at 2Ɵ: 31.023°:100%, 34.335°:70.%, and 27.777°:56% and JCPDS no.01-074-0566 of Ca10(PO4)6(OH)2 hexagonal at 2Ɵ (hkl): 31.766° (211):100%, 32.897°(300): 61.3%, 32.195°(112):51.5%, 25.883°(002):35.7%, and 49.490° (213):31.3%, respectively [3, 11-12]. Molar ratio (Ca:P) of hydroxyapatite (HA, Ca10(PO4)6(OH)2) is 1.67:1 whereas the molar ratio (Ca:P) of tricalcium phosphate (TCP, Ca3PO4)2 is equal to 1.5:1. The mixed phases between calcium hydroxyapatite and tricalcium phosphate called biphasic calcium phosphate [12]. Microstructures of Raw Duck Eggshell and Calcium Hydrogen Phosphate SEM micrographs of raw duck eggshells ground for 120 min, calcium hydrogen phosphate before firing, calcium hydrogen phosphate powder fired at 800°, 900°, and 1000°C at the magnifications of 1,000 and 5,000 times are shown in Figs. 2a, 2b, 2c, 2d, and 2e, respectively. SEM micrograph of raw duck eggshells ground for 120 min shows particle size distribution less than 50 µm and some agglomeration consistent with the result in Fig.1. Figs. 2b, 2c, 2d, and 2e shows the same irregular and agglomerate microstructures of calcium hydrogen phosphate before and after firing at 800º, 900º, and 1000ºC.

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Hydroxyapatite fired at 1000°C

Calcium phosphate fired at 900°C

Calcium phosphate fired at 800°C

Calcium hydrogen phosphate before firing

Duck eggshell fired at 900°C

Raw duck eggshells

Figure 1 XRD peak patterns of raw duck eggshell before and after calcination at 900°C for 2 hr, dried calcium hydrogen phosphate before firing, and calcium hydrogen phosphate powder after firing at 800°, 900°, and 1000°C, at each firing temperature for 2 hr, respectively.

a)

d)

b)

c)

e)

Figure 2 SEM micrographs of samples: a) duck eggshells ground for 120 min, b) calcium hydrogen phosphate before firing, c) sample fired at 800°C, d) sample fired at 900°C, and e) sample at 1000°C.


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Conclusions Duck eggshell, one kind of raw material, can react to phosphoric acid and fired at 1000ºC for 2 hr to form hydroxyapatite with the high percentage of ceramic yield 69.73. The average particle size, specific surface area, porosity, and density values of hydroxyapatite fired at 1000ºC are equal to 39.92 µm, 2.12 m2/g, 98.96 Å, and 3.02 g/cm3, respectively. The XRD peak pattern of calcium phosphate sample fired at 1000°C for 2 hr consistent with the JCPDS no.01-074-0566 shows Ca10(PO4)6(OH)2 hexagonal phase formation at 2Ɵ i.e. 31.766º, 32.897º, 32.195º, 25.883º, and 49.490º. The hydroxyapatite is a good bio-ceramic material suitable for use in medical and dental applications. Furthermore, the advantages of hydroxyapatite made from raw duck eggshell are compatibility, bioactivity, non-toxic, easy to preparation, low price, and high purity. Acknowledgements The authors sincerely thank the Department of Materials Engineering and the Energy and Environmental Engineering Center, Faculty of Engineering, Kasetsart University for eggshell classification and for the use analytical instruments. This work is grant supported from Agricultural Research Development Agency (Public Organization) or ARDA of Ministry of Agricultural and Cooperatives, the Thailand Research Fund encoded PRP5605010080. In addition, we also would like to acknowledge the financial supports from the Conductive and Electroactive Polymers Research Unit of Chulalongkorn University, the Thailand Research Fund (TRF), and the Royal Thai Government. References [1] S.W. Lee, S. G. Kim, C. Balázsi, W. S. Chae, and H. O. Lee, Comparative study of hydroxyapatite from eggshells and synthetic hydroxyapatite for bone regeneration, J. Oral Maxillofac. Surg., 113/3(2012), 348-355. [2] K. Lin, C. Wu, and J. Chang, Advances in synthesis of calcium phosphate crystals with controlled size and shape, Acta Biomater., 10 (2014), 4071-4102. [3] D. L. Goloshchapov, V. M. Kashkarov, N. A. Rumyantseva, P. V.Seredin, A. S. Lenshin, B. L. Agapov, and E. P. Domashevskaya, Synthesis of nanocrystalline hydroxyapatite by precipitation using hen’s eggshell, Ceram. Int., 39 (2013), 4539-4549. [4] S. S. Mehdi, M. T. Khorasani, D. K. Ehsan, A. Jamshidi, Synthesis methods for nanosized hydroxyapatite with diverse structures, Acta Biomater., 9 (2013), 7591-7621. [5] K. S. Vecchio, X. Zhang, J. Massie, M. Wang, and Ch. W. Kim, Conversion of bulk seashells to biocompatible hydroxyapatite for bone implants, Acta Biomater., 3 (2007), 910-918. [6] S. J. Lee, S. H. Oh, Fabrication of calcium phosphate bioceramics by using eggshell and phosphoric acid, Mater. Lett., 57 (2003), 4570-4574. [7] Y.Zhang, G.Yin, S.Zhu, D.Zhou, Y.Wang, Y.Li, and L.Luo, Preparation of β-Ca3(PO4)2 bioceramic powder from calcium carbonate and phosphoric acid, Curr. Appl. Phys., 5 (2005), 531-534. [8] J. Brzezińska-Miecznik, K.Haberko, M.Sitarz, M.M.Bućko, and B.Macherzyńska, Ceram. Int., 41 (2015), 4841-4846. [9] J. Chou, B. Ben-Nisson, A. H. Choi, R. Wuhrer, D. Green, Conversion of coral sand to calcium phosphate for biomedical applications, J. Aust. Ceram.Soc., 45 (2007), 44-48. [10] M. Sivakumar, T.S. Sampath Kumar, K.L. Shantha, K. Panduranga Rao, Development of hydroxyapatite derived from Indian coral, Biomater., 17 (1996), 1709-1714. [11] N. Tangboriboon, R. Kunanuraksapong, and A. Sirivat, Preparation and properties of calcium oxide from eggshells via calcination, Mater. Sci.-poland, 30/4 (2012), 313-322. [12] W. F. Ho, H. C. Hsu, S. K. Hsu, C. W. Hung, and S. C. Wu, Calcium phosphate bioceramics synthesized from eggshell powders through a solid state reaction, Ceram. Int., 39(2013), 6467-6473.

Advanced Materials, Structures and Mechanical Engineering II 10.4028/www.scientific.net/AMM.851

Innovative Preparation Calcium Hydroxyapatite from Duck Eggshell via Pyrolysis 10.4028/www.scientific.net/AMM.851.8 DOI References [1] S.W. Lee, S. G. Kim, C. Balázsi, W. S. Chae, and H. O. Lee, Comparative study of hydroxyapatite from eggshells and synthetic hydroxyapatite for bone regeneration, J. Oral Maxillofac. Surg., 113/3(2012), 348355. 10.1016/j.tripleo.2011.03.033 [2] K. Lin, C. Wu, and J. Chang, Advances in synthesis of calcium phosphate crystals with controlled size and shape, Acta Biomater., 10 (2014), 4071-4102. 10.1016/j.actbio.2014.06.017 [3] D. L. Goloshchapov, V. M. Kashkarov, N. A. Rumyantseva, P. V. Seredin, A. S. Lenshin, B. L. Agapov, and E. P. Domashevskaya, Synthesis of nanocrystalline hydroxyapatite by precipitation using hen's eggshell, Ceram. Int., 39 (2013), 4539-4549. 10.1016/j.ceramint.2012.11.050 [4] S. S. Mehdi, M. T. Khorasani, D. K. Ehsan, A. Jamshidi, Synthesis methods for nanosized hydroxyapatite with diverse structures, Acta Biomater., 9 (2013), 7591-7621. 10.1016/j.actbio.2013.04.012 [5] K. S. Vecchio, X. Zhang, J. Massie, M. Wang, and Ch. W. Kim, Conversion of bulk seashells to biocompatible hydroxyapatite for bone implants, Acta Biomater., 3 (2007), 910-918. 10.1016/j.actbio.2007.06.003 [6] S. J. Lee, S. H. Oh, Fabrication of calcium phosphate bioceramics by using eggshell and phosphoric acid, Mater. Lett., 57 (2003), 4570-4574. 10.1016/s0167-577x(03)00363-x [7] Y. Zhang, G. Yin, S. Zhu, D. Zhou, Y. Wang, Y. Li, and L. Luo, Preparation of β-Ca3(PO4)2 bioceramic powder from calcium carbonate and phosphoric acid, Curr. Appl. Phys., 5 (2005), 531-534. 10.1016/j.cap.2005.01.026 [8] J. Brzezińska-Miecznik, K. Haberko, M. Sitarz, M.M. Bućko, and B. Macherzyńska, Ceram. Int., 41 (2015), 4841-4846. 10.1016/j.ceramint.2014.12.041 [10] M. Sivakumar, T.S. Sampath Kumar, K.L. Shantha, K. Panduranga Rao, Development of hydroxyapatite derived from Indian coral, Biomater., 17 (1996), 1709-1714. 10.1016/0142-9612(96)87651-4 [11] N. Tangboriboon, R. Kunanuraksapong, and A. Sirivat, Preparation and properties of calcium oxide from eggshells via calcination, Mater. Sci. -poland, 30/4 (2012), 313-322. 10.2478/s13536-012-0055-7 [12] W. F. Ho, H. C. Hsu, S. K. Hsu, C. W. Hung, and S. C. Wu, Calcium phosphate bioceramics synthesized from eggshell powders through a solid state reaction, Ceram. Int., 39(2013), 6467-6473. 10.1016/j.ceramint.2013.01.076