Control of the alumino-silico-phosphate geopolymers properties and structures by the phosphorus concentration

Abstract Acid-based geopolymers are interesting materials, as they usually present higher mechanical and thermal properties than their alkali-based counterparts do, but difficult to use for complex shapes due the high viscosity of reactive mixture. This can be overcome by addition water in formulation. In this study, have been synthesized from metakaolin phosphoric acid with variable [P] concentration (by a modification either content or Al/P ratio). Measurements viscosity, density consolidation times performed on mixtures differentiated content. Furthermore, study geopolymers’ microstructure confirmed evolution [P]. Finally, characterization structural analyzes structure (Fourier transform infrared spectroscopy X-ray diffraction), carried out order assess influence different amorphous networks. It appears that influences material, it leads formation new More specifically, Al/P = 1 amounts, networks mainly based coexistence Al–O–P an hydrated silica network, while Al/P, network coexists unreacted metakaolin. addition, seems all governed parameter nP/nAl + nH2O.