DEINTERCALATION OF HYDRAZINE-INTERCALATED LOW-DEFECT KAOLINITE

Abstract--The deintercalation f a low-defect kaolinite intercalated with hydrazine was studied by X-ray diffraction, diffuse reflectance infrared spectroscopy (DRIFT), and Raman microscopy over 30 d. X-ray diffraction showed that the kaolinite was fully intercalated. More than 120 h were required for the hydrazine-intercalate to decompose. The Raman spectra of the hydrazine intercalate showed only a single band at 3620 cm 1, which was attributed to the inner-hydroxyl group. Upon deintercalation, additional Raman bands were observed at 3626 and 3613 cm 1. These bands decreased in intensity with further deintercalation. As deintercalation proceeded, the bands assigned to the inner-surface hydroxyl groups at 3695, 3682, 3670, and 3650 cm-1 occurred and increased in intensity. DRIFT spectra showed two bands at 3620 and 3626 cm-1 for the fully intercalated kaolinite only. Upon deintercalation, anadditional band assigned to intercalated water was observed at 3599 cm ~ and increased in intensity at the expense of the 3626-cm ~ band. Bands attributed to the inner-surface hydroxyl groups increased in intensity with dein-tercalation. Both the Raman and DRIFT spectra showed complexity in the NH-stretching region with two sets of NH-symmetric and antisymmetric stretching bands. Deintercalation was followed by the loss of intensity of these bands. Significant changes were also observed in the hydroxyl deformation and water-bending modes as a result of deintercalation. A model of hydrazine intercalation of kaolinite based o