Preparation of γ-Al2O3 and Prioritization of Affecting Factors on the Crystallite Size Using Taguchi Method

Document Type: Original Research Paper

Authors

1 Deparetment of Chemical Engineering, University of Sistan and Bluchestan, Zahedan, Iran

2 Department of Materials Engineering, University of Sistan and Bluchestan, Zahedan, Iran

Abstract

In this work, boehmite sol was prepared by a previously applied and validated method; hydrolysis of aluminum chloride hexa-hydrate. In order to obtain precise results, the effect of pH after adding precipitating agent, aging time, peptizing temperature and ultrasonic vibration time on the crystallite size of final precipitate were investigated in a narrow range. The preparation conditions applied in the production step of nanocrystalline boehmite affected on the desired alumina phase. Experiments were set based on the statistical design of experiments (Taguchi method). Furthermore the influence of calcination on crystallization and phase transformation of the precipitate was investigated using X-ray diffractometry (XRD) and simultaneous thermal analysis (STA) techniques. To evaluate the results, the obtained data were statistically analyzed. Considering the statisti cal analysis of experiments, the pH after adding precipitating agent is the major parameter affecting crystallite size. In contrast, aging time has the smallest effect on the crystallite size. In addition, Transmission electron microscopy (TEM) of the samples revealed that the particle size of the powders was well distributed in the nano-size range. Taguchi prediction on the crystallite size was 2.096±0.139 nm (with confidence interval of 95%) which confirmed by a verification experiment (2.064 nm).

Keywords


[1] R.R. Bhave, Inorganic Membranes:Characterizationand application, New York, van Nostrand Reinhold(1991) 1- 24.

[2] K.A. DeFriend, M.R. Wiesner, A.R. Barron,Alumina and aluminate ultrafiltration membranesderived from alumina nanoparticles, J. MembrSci. vol. 224 (2003) 11-28.

[3] Y. Cho, K. Han, K. Lee, separation of CO2 bymodified _-Al2O3 membranes at high temperature, J.Membr Sci. 104 (1995) 219.

[4] X. Changrong, W. Feng, M. Zhaojing, L.Fanqing , P. Dingkun, M. Guangyao, Boehmite solproperties and preparation of two-layer aluminamembrane by a sol-gel process, J. Membr Sci. 116(1996) 9-16.

[5] M.L. Panchula, J.Y. Ying , Mechanical Synthesisof Nanocrystalline _-Al2O3 Seeds for EnhancedTransformation Kinetics, Nanostruct Mater. 9(1997) 161.

[6] K. Kamata, T. Mochizuki, S. Matsumoto, A.Yamada, K. Miyokawa, Preparation ofsubmicrometer Al2O3 powder by gas-phaseoxidation of tris(acetylacetonato) alumina (III), J.Am Ceram Soc. 68 (8) (1985) C-193–C-194.

[7] J.G. Li, X.D. Sun. Synthesis and sintering behaviorof a nanocrystalline _-Al2O3 powder, Acta Mater. 48(2000) 3103-3112.

[8] J.J. Kingsley, K.C. Patil, A novel combustionprocess for the synthesis of fine particle _- aluminaand related oxide materials, Mater Lett. 6 (1988)427–432.

[9] S.A. Hassanzadeh-Tabrizi, E. Taheri-Nassaj,H. Sarpoolaky, Synthesis of an alumina–YAGnanopowder via Sol-Gel method, J Alloy Compd.456 (2008) 282-285.

[10] R. Tipakontitikul, A. Niyompan, K. Srisurat, N.Kanchanarat, T. Tunkasiri, Effect of pH onPhase Formation and Morpholo of theNanocrystalline Boehmite Powder Prepared by aPrecipitation Method, Journal of Micros copySociety of Thailand 22 (2008) 20-22.

[11] W. Tsunenori, M. Yoshihisa, M. Takeo, K.Hiroyoshi, H. Saburo, W. Kenji, I. Masashi,Pore structure of c-Ga2O3–Al2O3 particlesprepared by spray pyrolysis, Micropor MesoporMat. 145 (2011) 131-140.

[12] R. Brace, E. Matijevic, Aluminium hydrousoxide sols: I, J. Inorg Nucl Chem. 35 (1973)3691–3705.

[13] S.A. Hassanzadeh-Tabrizi, E. Taheri-Nassaj,Economical synthesis of Al2O3 nanopowderusing a precipitation method”, Mater Lett.63 (2009) 2274-2276.

[14] H. Kwang-Taek, L. Hee-Soo, L. Shi-Hee, C.Koo-Chun, P. Shin-Seo, L. Jae-Hoon, Synthesis ofaluminum hydrates by a precipitation method andtheir use in coatings for ceramic membranes, J EurCeram Soc. 21 (2001) 375-380.

[15] V. Francetic, P. Bukovec, Peptization and Al-Keggin Species in Alumina Sol, Acta ChimSlov. 55 (2008) 904- 908.

[16] H. Beygi, M. Zare, S.A. Sajjadi, Fabrication ofFeNi–Al2O3, nanocomposites and optimizationof mechanical properties using Taguchi method,Powder Technology 232 (2012) 49–57.

[17] S. H. Sadeghi, V. Moosavi, A. Karami, N.Behnia, Soil erosion assessment and prioritization ofaffecting factors at plot scale using the Taguchimethod, Journal of Hydrology, 448–449 (2012) 174–180.

[18] X. Bokhimi, J.A. Toledo-Antonio, M.L.Guzman-Castillo, B. Mar-Mar, F. Hernandez-Beltran, J. Navarette, Dependence of BoehmiteThermal Evolution on Its Atom Bond Lengths andCrystallite Size, J. Solid State Chem. 161 (2001)319-326.

[19] K. Okada, T. Nagashima, Y. Kameshima, A.Yasumori, T. Tsukada, Relationship betweenFormation Conditions, Properties, and CrystalliteSize of Boehmite, J Colloid Interf Sci. 253 (2002)308–314.

[20] J.M. Rousseaux, P. Weisbecker, H. Muhr, E.Plasari, Aging of Precipitated Amorphous AluminaGel, Ind Eng Chem Res. 41 (2002) 6059-6069.

[21] Y. Raghvendra, M. Priya, P. Avinash, Growthmechanism and optical property of ZnOnanoparticles synthesized by sonochemical method,Ultrason Sonochem 15(2008) 863–868