Preparation, Characterization, and Application of Metakaolin-Based Geopolymer for Removal of Methylene Blue from Aqueous Solution

Table 4

FTIR bands (cm⁻¹) of kaolin, metakaolin, and geopolymer.

Bands (cm^−1)			Assignments	References
Kaolin	Metakaolin	Geopolymer
3550	—	—	Stretching and deformation of OH	[38]
3410	—	—	Stretching and deformation of OH	[34]
1622	—	—	Stretching and deformation of OH	[34]
1436	—	—	Stretching vibration of O-C-O	[39]
1151	—	1111	Si-O-Si bending vibration	[40]
988	988	979	Stretching vibration of Si-O-T (T = Al or si)	[41]
757	757	—	Bending vibration of Si-O-Al	[42]
662	662	664	Bending vibration of Si-O-Al	[43]
593	593	—	Bending vibration of Si-O-Al	[44]
532	553	553	Bending vibration of Si-O-Al	[45]
437	446	446	Bending vibration of Si-O-Si	[46]