Influence of Hydrazine on the Vibrational Modes of Kaolinite

Abstract

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 OHstretching 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 -~ 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 A. Partial collapse of the intercalate from 10.4 to 9.6 A was probably due to keying of the -NH2 moiety ofhydrazine into the siloxane ditrigonal cavity, as indicated by a blue-shift of the inner-OH band from 3620 to 3628 cm ~. Structural OH vibrational modes may therefore be useful probes of amine interactions with clay mineral surfaces.

Complexity of Intercalation of Hydrazine into Kaolinite—A Controlled Rate Thermal Analysis and DRIFT Spectroscopic Study

“…Johnston et al also reported two bands at 3368 and 3363 cm -1 for the 10.3Å phase of hydrazine-intercalated kaolinite and that these two bands coalesced into a single band at 3363 cm -1 for the 9.5Å phase (6,10). In this work we find two bands at 3356 and 3362 cm -1 , which are present for both the 10.3 and 9.5Å phases.…”

Thermal Decomposition of a Dickite-Hydrazine Intercalation Complex

“…These authors also demonstrated that a variable fraction of the starting sample does not react with hydrazine, whereas some kaolinite specimens react slowly and lead to complexes with a basal spacing of 9.5-9.6 A. A similar spacing was observed by Johnston and Stone (1990) during hydrazine loss at decreasing pressure, and this was interpreted as relating to the structural rearrangement caused by the loss of a portion of the intercalated hydrazine. Frost et aL (1998) and Kloprogge et al (1999) showed XRD patterns of K-H complexes with broad basal reflections, consisting of three overlapped peaks with d values of 10.28, -9.50, and -8.80 A.…”

“…This intermediate intercalation complex also showed a d value slightly lower than the 9.6 ,~ measured in the K-H complex. This "contracted" complex was observed by Johnston and Stone (1990) during hydrazine loss at decreasing pressure and interpreted, from IR spectra, as owing to the keying of the hydrazine molecules into the ditrigonal cavities of the tetrahedral sheet. Recently, Frost et al (1998) and Kloprogge et al (1999) proposed that intercalation takes place in steps.…”

“…The reagent used was 98% pure hydrazine monohydrate (Prolabo Company, Fontenay, France). The D-H intercalation complex was obtained by two different methods (Johnston and Stone, 1990): 1) Dickite (0.5 g) was mixed with 10 cm 3 hydrazine monohydrate for lengths of time ranging from 1 h to 7 d. The mixture was sealed, maintained at room temperature, and the excess solution was separated by centrifugation. 2) A few drops of hydrazine were placed on an oriented sample of dickite.…”

“…Intercalation of hydrazine in the interlayer of kaolin minerals has been extensively studied by X-ray diffraction (XRD) and spectroscopic methods (Weiss et al, 1963;Ledoux and White, 1966;Wada and Yamada, 1968;Range et al, 1969;Jackson and AbdelKader, 1978;Theng et al, 1984;Johnston, 1990;Johnston and Stone, 1990;Gfibor et aL, 1995;Frost et aL, 1998;Kloprogge et al, 1999;Krist6f et al, 1997Krist6f et al, , 1999Ruiz Cruz and Franco, 2000). Most of these studies involve the kaolinite-hydrazine (K-H) complex, and especially the characterization of kaolinites with various degrees of lattice disorder (e.g., Range et al, 1969;Fernfindez Gonzfilez et al, 1976;G~ibor et al, 1995;Kloprogge et al, 1999), whereas the dickitehydrazine (D-H) and nacrite-hydrazine (N-H) complexes have received less attention.…”