Investigation of the Orientation of CTA⁺ Ions in the Interlayer of CTAB Pillared Montmorillonite

Table 4

Positions and assignments of the IR vibration bands observed in the range of 400–4000 cm⁻¹.

Assignment	Frequency, cm^−1
	Mt	0.5 CEC	1.0 CEC	1.5 CEC	2.0 CEC
Structural OH stretching	3634	3633.09	3633.14	3629.92	3624.39
Symmetric OH stretching (𝜈1)	3444	3435.98	3435.09	3434.57	3434.74
Asymmetric OH stretching (𝜈3)	—	—	—	—	—
Asymmetric CH2 stretching	—	2931.17	2924.2	2919.77	2918.98
Symmetric CH2 stretching	—	2855.75	2851.49	2850.57	2850.29
H–O–H bending (𝜈2)	1642	1640.09	1638.01	1637.21	1633.37
CH2 scissoring	1478	1476	1474.03	1473.07	1472.98
	1442	1440.09	1438.01	1437.21	1433.37
Si–O stretching	1018.43	1000.38	1036	1029	1022
	1101	1088	914.73	918	914.73
CH2 rocking	797.47	797.16	797.16	798.08	797.17
	779.18	779.43	778.43	779.81	778.80