The modification of sodium montmorillonite (MMT-Na) through the incorporation of n-hexadecyltrimethylammonium chloride (HTACl) cations into the clay's interlayer spaces has been studied. Alkylammonium concentrations equivalent to 10-200% times the cation exchange capacity of the clay were used. The conformation of the surfactant cations in the confined space of the silicate galleries was investigated by X-ray diffraction analysis, scanning electron microscopy and Infrared spectroscopy (IR). High resolution thermogravimetric analysis shows that the thermal decomposition of modified montmorillonite occurs in three steps. The first step of mass loss is related to dehydration of adsorbed water and water hydrating metal cations such as Na +. The second step of mass loss is attributed to the decomposition of surfactant. The third step is due to the loss of OH units during the dehydroxylation of the montmorillonite. The conformation of the surfactant cations in the confined space of the silicate galleries is investigated by X-ray diffraction analysis. These analyses are very important for any attempt to incorporate the organomodified montmorillonite (OMMT) particles into different media for various applications such as polymer nanocomposite preparation.

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Montmorillonite-Fe3+ (MMT-Fe3+) nanoclay mineral was successfully prepared using a ferric chloride precursor. The prepared sample was characterized using IR, XRD, BET and SEM-EDX. We have explored the highly efficient and environmentally benign MMT-Fe3+ for adsorption of Crystal Violet (CV) dye from aqueous solution under ambient conditions. The MMT-Fe3+ was interacted with CV dye solution at different pH, temperature and solid-to-liquid ratio. The concentration of CV dye removal was estimated from its optical density at λmax = 590 nm using UV–Vis spectrophotometer. The CV dye removal was rapid at basic pH and increases with temperature up to 40 °C. A complete reduction (100%) was occurred in about 7 min at pH 7 and 10 while at pH 3 in about 10 min. The time taken for complete reduction at 0, 30 and 40 °C are 10, 7 and 5 min respectively. The removal followed by adsorption of dye molecules on the spent nanoclay mineral was evident from SEM/EDX analysis. More importantly, MMT-Fe3+ could be separated and retrieved easily after the reaction by centrifugation from the degraded CV dye solution. The experimental results of CV dye removal from MMT-Fe3+ follows the pseudo first order kinetics. This study reveals that MMT-Fe3+ has the potential to be used as reductant/adsorbant to remove cationic pollutants effectively and rapidly from drinking water and large scale of industrial wastewater.