Synthesis and characterization of Na-montmorillonite-alkylammonium intercalation compounds

Some organophilic montmorillonites (OPMNTs) have been synthesized from Na-montmorillonite (Na-MNT) using ammonium salts of methyl, propyl, butyl, and dodecyl amine. Thermogravimetric (TG), infrared (IR), and X-ray analyses of the compounds were carried out. Microstructural parameters such as crystallite size and root mean square strain (rms) (<e2>1/2) have been calculated by X-ray line profiles analysis. TG analysis in the temperature range 20–100°C show a weight loss for pure Na-MNT and OPMNTs of about 11% and 2.8%, respectively, indicating the organophilic properties of the OPMNTs. IR and X-ray analyses confirm the formation of OPMNTs by an ion exchange reaction. It is also observed that the crystallite size and rms strain increase with increase carbon number (nc) in the amines.