Preparation and characterization of montmorillonite-cetyl trimethylammonium bromide

Abstract

The research was focused on the modification of natural montmorillonite by using cationic surfactant cetyl trimethylammonium bromide (CTAB). The natural bentonite was washed with distilled water to clean the impurites of nature bentonite in order to get the montmorillonite fraction. A variation of the amount of CTAB, which is used for the preparation of organo-montmorillonite is 0.5; 1.0; 1.5; 2.0; 2.5 CEC of montmorillonite. The organically intercalated montmorillonite composites were characterized by FT-IR, XRD, Brunauer-Emmett-Teller (BET) surface area techniques and SEM-EDX-Mapping methods. The effect of addition of CTAB on the basal spacing of montmorillonite was observed with XRD, indicating an increase in basal spacing (d001) of montmorillonite 14.671 (2θ = 6.02) to 19.153 Å (4.61°). The main bands of untreated montmorillonite at 3626 cm–1 attributed to stretching vibration of structural hydroxyl groups (-OH) and 1041 cm–1 assigned to Si-O stretching vibration. The spesific bands of organo montmorillonite which appeared at 2924 and 2854 cm–1 are corresponding to stretching asymmetric vibration νas(CH2) and stretching symmetric νs(CH2), respectively. The C-H stretch of CTA+ structure in-plane binding was noticed at 1473 cm–1. The bands at 516 and 462 cm–1 were assigned to the Al-O-Si (octahedral layer) bend for untreated and organo-montmorillonite, respectively. The BET specific surface area reduced with increasing surfactant concentrations.