Table 3.

Frequencies of the absorption bands (cm⁻¹) taken from the spectra (Fig. S4. in Supplementary file) of the geopolymer samples.

Mix ID	Wavenumber (cm−1)
	Assignment
	O–H stretching vibration	H–O–H molecular bending	C–O (sodium, calcium) carbonates stretching mode	Si–O-T (T = Si, Al; where Si and Al are tetrahedral), and asymmetric stretching, O–C–O stretching mode	Si–O–Si bond (presence of quartz), symmetric stretching	Si–O–Si/Al–O–Si, symmetric stretching, or C–O out of plane bending
GM-0.5-0	3467	1642	1432	1031	797	714
GM-1-0	3460	1640	1428	1035	798	713
GM-1.5-05	3437	1641	1428	1035	798	713
GM-0.5-05	3439	1639	1431	1039	798	711
GM-1-05	3438	1638	1437	1035	798	714
GM-1.5-05	3434	1640	1450	1035	798	713
GM-0.5-1	3462	1641	1438	1040	798	714
GM-1-1	3437	1641	1435	1036	798	714
GM-1.5-1	3437	1641	1455	1031	796	713