Dissolution-Reorientation-Polycondensation Process of Metakaolin in Alkaline Solutions Related to Geopolymerization

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Abstract:

Geopolymer is a novel type of inorganic cementitious materials, which has become a hot topic across the world. Geopolymerization process of metakaolin in alkaline solutions shows important effects on final properties of hardened geopolymer. In this paper all the possible reaction pathways involved in the dissolution-reorientation-polycondensation process of metakaolin in alkaline solution were studied according to thermodynamic theory. The corresponding reaction energy of every possible pathway was also calculated using computation chemistry methodsemi- empirical AM1 calculation. The optimum reaction pathway was analysized based on the energy-minimized principle. The calculation results showed that highly alkaline accelerated the dissolution of 6-membered tetrahedron rings of SiO4 or AlO4 tetrahedron representing the molecular structure of metakaolin during dissolution process. Si-Al hybrid reorientation should theoretically be primary reorientation pathway during reorientation process. Framework clusters should be primary polycondensation products during polycondensation process. The above studies enhanced our understanding of formation mechanisms of metakaolin in alkaline solutions related to geopolymerization.

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41-50

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October 2010

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[1] J. Davidovits: J. Therm. Anal. Vol 35 (1989), pp.429-441.

Google Scholar

[2] J. Davidovits, in: Proceedings of the First European Conference on Soft Mineralog, edtied by J. Davidovits and J. Orlinsl, Vol. 1, The Geopolymer Institute, France, Compiegne, (1988), pp.25-48.

Google Scholar

[3] J. Davidovits, in: Ceramic Transactions, Cement-based materials: present, future, and environmental aspects, edited by M. Moukwa, S.L. Sarkar, K. Luke and M.W. Grutzeck, American Ceramic Society, America, (1993), pp.165-182.

Google Scholar

[4] R. Nowak: The New Sci. Vol 197 (2008), pp.28-29.

Google Scholar

[5] J. Davidovits, C. D. Comrie, J.H. Paterson and D.J. Ritcey: Concr. Int. Des. & Constr. Vol 12 (1990), pp.30-40.

Google Scholar

[6] J.G.S. Van Jaarsveld, J.S.J. Van Deventer: Miner. Eng. Vol 10 (1997), pp.659-669.

Google Scholar

[7] R.E. Lyon, A. P.N. Foden, Balaguru, M. Davidovits, J. Davidovits: J. Fire Mater. Vol 21 (1997), pp.67-73.

DOI: 10.1002/(sici)1099-1018(199703)21:2<67::aid-fam596>3.0.co;2-n

Google Scholar

[8] A. Palomo, M.T. Blanco-Varela, M.L. Granizo: Cem. Concr. Res. Vol 29 (1999), pp.997-1004.

Google Scholar

[9] M. Sofi, J.S.J. van Deventer, P.A. Mendis: Cem. Concr. Res. Vol 37 (2007), pp.251-257.

Google Scholar

[10] W. Hongling, L. Haihong and Y. Fengyuan: Coll. Surf. A Vol 268 (2005), pp.1-6.

Google Scholar

[11] J.G.S. Van Jaarsveld, J.S.J. Van Deventer and A. Schwartzman: Miner. Eng. Vol 12 (1999), pp.75-91.

Google Scholar

[12] J. Davidovits: Concr. Int. Vol 16 (1994), pp.53-58.

Google Scholar

[13] J.G.S. Van Jaarsveld, J.S.J. Van Deventer, L. Lorenzen: Metall. Mater. Trans. B Vol 29 (1998), pp.283-291.

Google Scholar

[14] X. Hua, J.S.J. Van Deventer: Int. J. Miner. Process Vol 59 (2000), pp.247-266.

Google Scholar

[15] J. Davidovits, in: Concrete technology, past, present, and future, edited by P.K. Mehta, American Concrete Institute, Detroit, (1994), pp.383-397.

Google Scholar

[16] A. Palomo, M.W. Grutzeck, M.T. Blanco: Cem. Concr. Res. Vol 29 (1999), pp.1323-1329.

Google Scholar

[17] J. Davidovits, in: Proceedings of Geopolymere '99, edited by J. Davidovits, Saint-Quentin, France, (1994), pp.83-96.

Google Scholar

[18] Z. Yunsheng, S. Wei, L. Zongjin: J. Mater. Sci. Vol 42 (2007), pp.3015-3023.

Google Scholar

[19] Z. Yunsheng, J Yatao, S. Wei, L. Zongjin: Cem. Concr. Res. Vol 39 (2009), pp.1174-1179.

Google Scholar

[20] Z. Yunsheng, S. Wei, L. Zongjin: Adv. Cem. Res. Vol 21 (2009), pp.67-73.

Google Scholar

[21] F. Liebau: Structural Chemistry of Silicates:Structure, Bonding Formation and Classification. (Springer, Berlin 1985).

Google Scholar

[22] A.V. McComick, A.T. Bell, C.J. Raddke: J. Phys. Chem. Vol 93(1989), pp.1733-1737.

Google Scholar

[23] A.V. McComick, A.T. Bell, C.J. Raddke: J. Phys. Chem. Vol 93(1989), pp.1737-1741.

Google Scholar

[24] A.V. McComick, A.T. Bell, C.J. Raddke: J. Phys. Chem. Vol 93(1989), pp.1747-1744.

Google Scholar

[25] T.W. Swaddle, J. Salerno, P.A. Tregloan: Chem. Soc. Rev. Vol 23 (1994), pp.319-325.

Google Scholar

[26] W. Loewenstein: Amer. Miner. Vol 39 (1954), pp.92-96.

Google Scholar