This study investigated the effect of alkali activation process conditions on the IR spectra, on which
amount and types of zeolites in the resultant geopolymers influence significantly. Kaolinite was used as
starting materials. The kaolinitic clay was first calcined to transform into the amorphous aluminosilicate
phases (metakaolinite) and then activated with sodium silicate (as water glass) and sodium hydroxide.
The effects of reaction systems composition (expressed as SiO2/Al2O3 and Al2O3/Na2O molar ratios) as
well as synthesis temperature on the phase composition of obtained products have been determined. In
particular, the structures of materials were examined using FT-IR spectroscopy in the middle infrared
range. The results were compared to the XRD measurements, as well as SEM observations.
Alkali-activation treatment of the metakaolin yielded bulk materials with different amounts and types
of zeolite, which reveal the IR spectra of received materials. With proper selection of the initial conditions
(temperature and composition), it is possible to obtain a solid material containing zeolite phase
such as zeolite X, zeolite A or sodalite. The presence of zeolite phase was confirmed by the measurement
of spectra in the middle infrared. In particular in pseudolattice range of the spectra, i.e. 800e400 cm1,
there are bands associated with the ring vibrations, which are characteristic for secondary building units
(SBU) occurred in zeolite structure. IR spectroscopy is also useful in the studies of resulting amorphous
phase structure.