Effect of Soil Solution pH during the Tetracycline Intercalation on the Structural Properties of a Dioctahedral Smectite: Microstructural Analysis

Table 4

FTIR band position (cm^-1), respectively, for TC, Na-montmorillonite (SWy-2-Na), and TC sorption versus pH.

Sample	FTIR band position	Possible band assignment [38]
TC	1627	ν(CO1), ν(amid-NH), ν(CO3), ν(C2C3), δ(OH10,12)
	1572	δ(amid-NH), δ(amine-NH), ν(amid-CO), ν(C2C3), ν(CO3)
	1446	δ(OH10,12), δ(CH7,8,9), ν(D), ν(CO10,CO11), ν(C11C11a, C11aC12), δ(OH12a), δ(CH36)
	1350	ν(amid-C,C2), ν(C3,C4), δ(CH4a,5), δ(CH36), δ(OH12a), δ(amid-NH), ν(amid-CN), δ(OH10), ν(C6aC10a, C6aC7)
	1310	δ(OH10,12), δ(CH4,4a,5,5a), ν(C5aC11a), ν(C1C2), ν(C9C10, C10C10a, C10aC11), ν(CO11,12), ν(CO3), δ(CH7,8,9)
Na-montmorillonite (SWy-2-Na)	3620	OH stretching of structural hydroxyl groups
	3542	OH stretching of water coordinated to Al and Mg
	3415	OH stretching of adsorbed water
	1656	OH deformation of water
	1035	Si-O stretching
	980	Si-O stretching
MMT+TC; For pH: 3 ➔ 8	3621	OH stretching of structural hydroxyl groups
	3542	OH stretching of water coordinated to Al and Mg
	3417	OH stretching of adsorbed water
	1638	OH deformation of water
	1048	Si-O stretching
	980	Si-O stretching