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A platform for research: civil engineering, architecture and urbanism
Bulk modulus of basic sodalite, Na8[AlSiO4]6(OH)2·2H2O, a possible zeolitic precursor in coal-fly-ash-based geopolymers
Abstract Synthetic basic sodalite, Na8[AlSiO4]6(OH)2·2H2O, cubic, P43n, (also known as hydroxysodalite hydrate) was prepared by the alkaline activation of amorphous aluminosilicate glass, obtained from the phase separation of Class F fly ash. The sample was subjected to a process similar to geopolymerization, using high concentrations of a NaOH solution at 90°C for 24hours. Basic sodalite was chosen as a representative analogue of the zeolite precursor existing in Na-based Class F fly ash geopolymers. To determine its bulk modulus, high-pressure synchrotron X-ray powder diffraction was applied using a diamond anvil cell (DAC) up to a pressure of 4.5GPa. A curve-fit with a truncated third-order Birch–Murnaghan equation of state with a fixed K' o =4 to pressure-normalized volume data yielded the isothermal bulk modulus, K o =43±4GPa, indicating that basic sodalite is more compressible than sodalite, possibly due to a difference in interactions between the framework host and the guest molecules.
Bulk modulus of basic sodalite, Na8[AlSiO4]6(OH)2·2H2O, a possible zeolitic precursor in coal-fly-ash-based geopolymers
Abstract Synthetic basic sodalite, Na8[AlSiO4]6(OH)2·2H2O, cubic, P43n, (also known as hydroxysodalite hydrate) was prepared by the alkaline activation of amorphous aluminosilicate glass, obtained from the phase separation of Class F fly ash. The sample was subjected to a process similar to geopolymerization, using high concentrations of a NaOH solution at 90°C for 24hours. Basic sodalite was chosen as a representative analogue of the zeolite precursor existing in Na-based Class F fly ash geopolymers. To determine its bulk modulus, high-pressure synchrotron X-ray powder diffraction was applied using a diamond anvil cell (DAC) up to a pressure of 4.5GPa. A curve-fit with a truncated third-order Birch–Murnaghan equation of state with a fixed K' o =4 to pressure-normalized volume data yielded the isothermal bulk modulus, K o =43±4GPa, indicating that basic sodalite is more compressible than sodalite, possibly due to a difference in interactions between the framework host and the guest molecules.
Bulk modulus of basic sodalite, Na8[AlSiO4]6(OH)2·2H2O, a possible zeolitic precursor in coal-fly-ash-based geopolymers
Oh, Jae Eun (author) / Moon, Juhyuk (author) / Mancio, Mauricio (author) / Clark, Simon M. (author) / Monteiro, Paulo J.M. (author)
Cement and Concrete Research ; 41 ; 107-112
2010-09-24
6 pages
Article (Journal)
Electronic Resource
English
| British Library Online Contents | 2011
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