Adsorption of the quaternary ammonium salts on montmorillonite Original Research Article

Sodium montmorillonite SOMASIF® ME 100 (M) has been subjected to modification through ion-exchange reaction by a number of (alkyloxymethyl)dodecyldimethylammonium chlorides with the general formula [C12H25N+(CH3)2CH2OR]Cl−. The modified samples were studied by X-ray diffraction (XRD) technique, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM), and thermogravimetric analysis. The basal spacing of unmodified montmorillonite, determined by XRD, was 1.227 nm and after modification it increased up to 1.557 nm (montmorillonite modified with dodecyldimethyl(dodecyloxymethyl)ammonium chloride). The FTIR studies revealed structural differences between the modified and unmodified montmorillonite samples. The IR spectra of the modified montmorillonite showed the C–C stretching bands (1468 cm−1) and C–H vibrations (near 2930 and 2856 cm−1). Results of the SEM study revealed a tendency towards lump formation and agglomeration of the organophilised particles of montmorillonite.