Abstract
► Organo-bentonites were prepared at C16TMABr/CEC ratios up to 11. ► Disorder configuration of C16TMA cations was observed at higher C16TMABr/CEC ratios. ► The evolved gases during the calcinations of organoclays were analyzed by MS-TG. ► In situ XRD technique detected clearly the phase disorder in the range 50–150°C. ► Collapse of organoclays depended on the temperature and the used atmospheres.
Different concentrations of cetyl trimethylammonium bromide solutions were cation exchanged with bentonite clay mineral, at room temperature. The resulting organoclays were characterized by elemental analysis C and N, X-ray diffraction and thermal gravimetric analysis. The evolved gases during the calcination of organoclays were identified by online mass spectrometry coupled with thermal gravimetry technique. Meanwhile, in situ X-ray diffraction was used to have insight on the thermal stability of the organoclays in air atmosphere. X-ray diffraction at room temperature indicated that a disorder transition phase from bilayer to paraffin configuration occurred at higher surfactant-cation exchange capacity ratios, with two phases at 3.25 and 2.00nm, respectively. The in situ X-ray diffraction confirmed the presence of these two phases with improved reflections intensities in the range of 100–200°C. Above this temperature, both phases collapsed due to the decomposition of the surfactants as recorded by mass spectrometry thermal gravimetric analysis.