²⁹Si and ²⁷Al MAS-NMR Studies of Metakaolin Changes during the Polymerization of Mineral Polymer

Abstract:

Mineral polymer is a new category of inorganic non-mental materials, which was manufactured from metakaolin in this paper. Changes of metakaolin in the polymerization could be described as: (1) the glassy parts of the metakaolin were dissolved in the high molar alkaline solution and some SiO, AlO bonds of them broke; (2) at the presence of OH-and Na+, these broken bonds formed aluminosilicate gel and then transformed into zeolitic precursors with changing compositions and concentrations of the solution; (3) by dehydration, these zeolitic precursors changed into the amorphous phase materials. NMR analysis indicated that in the geopolymeric products cured for 28 days, Q⁴(2Al) was the principal form of Si element and the content of four coordinate Al was increasing with the reaction. The experimental results provided a good basis for understanding the reactive mechanism of polymerization during processing of geopolymer products.

• Periodical: Applied Mechanics and Materials (Volumes 543-547)
• Pages: 3818-3821
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.543-547.3818
• Online since: March 2014
• Authors: Yi Miao Nie*, Mao Hui Xia, Shu Xian Liu
• Keywords: Existence State of Al, Existence State of Si, MAS-NMR, Metakaolin (MK), Mineral Polymer

References

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[2] Y.M. Nie, H.W. Ma, J. Yang: GeoScience. Vol. 20 (2006), p.340. (in chinese).