Influence of Hydrazine on the Vibrational Modes of Kaolinite

C. T. Johnston1 and D. A. Stone2
1 Department of Soil Science, University of Florida, Gainesville, Florida 32611
2 HQ AFESC/RDVS, Tyndall AFB, Florida 32403

Abstract: Raman and Fourier-transform-infrared (FTIR) spectroscopic methods and X-ray powder diffraction (XRD) techniques have been used to study the influence of hydrazine on the vibrational modes of kaolinite. Strong vibrational perturbations of the OH-stretching and -deformation bands were observed in the Raman and FTIR spectra on intercalation. The intensities of the Raman- and IR-active OH-stretching bands decreased significantly upon intercalation; the intensities of the Raman bands were reduced to a greater extent than the IR bands. The deformation bands were also strongly perturbed by the presence of hydrazine in the interlamellar region. Upon evacuation of the intercalate, two new bands at 3628 and 912 cm-1 were noted, indicating the presence of a different structural conformation of the complex under vacuum. Similar results were obtained using XRD, on evacuation of the kaolinite-hydrazine (KH) complex the d(001) value decreased from 10.4 to 9.6 Å. Partial collapse of the intercalate from 10.4 to 9.6 Å was probably due to keying of the -NH2 moiety of hydrazine into the siloxane ditrigonal cavity, as indicated by a blue-shift of the inner-OH band from 3620 to 3628 cm-1. Structural OH vibrational modes may therefore be useful probes of amine interactions with clay mineral surfaces.

Key Words: Fourier-transform infrared spectroscopy • Hydrazine • Kaolinite • OH-vibration modes • Raman spectroscopy • X-ray powder diffraction

Clays and Clay Minerals; April 1990 v. 38; no. 2; p. 121-128; DOI: 10.1346/CCMN.1990.0380202
© 1990, The Clay Minerals Society
Clay Minerals Society (www.clays.org)