Degree of reactivity of two kaolinitic minerals in alkali solution using zeolitic tuff or silica sand filler

作者：Yousef Rushdi I^*; El Eswed Bassam; Alshaaer Mazen; Khalili Fawwaz; Rahier Hubert

来源：Ceramics International, 2012, 38(6): 5061-5067.

DOI：10.1016/j.ceramint.2012.03.008

• Geopolymers
• Inorganic polymers
• Kaolinite
• Zeolitic tuff

Four geopolymers were synthesized by NaOH-activation of a mixture of kaolinite (Jordanian kaolinite or Ukrainian kaolinite) and a filler (zeolitic tuff or silica sand). X-ray powder diffraction (XRD), Fourier-transform infrared spectrometry (FTIR), and solid-state magic angle spinning nuclear magnetic resonance (MAS-NMR) were employed to monitor the extent of reaction and to characterize the phases in the geopolymer. Remaining kaolinite in all produced geopolymer specimens unambiguously indicated an incomplete reaction. The Si-29 MAS-NMR spectra of the geopolymers revealed the presence of tetrahedral-SiO4 whereas the Al-27 MAS-NMR spectra revealed the presence of both tetrahedral-AlO4 and octahedral-AlO6. The XRD patterns of geopolymers showed the formation of a new feldspar mineral. Replacing silica sand filler by zeolitic tuff enhanced markedly the specific surface area of the corresponding geopolymers.

• 出版日期2012-8