New Approach to the Problem of the Interlayer Bonding in Kaolinite

Abstract

Abstract--The possibility of recording the absorption band which is related to oscillations of free OH in a superficial plane of the octahedral sheet of kaolinite inspired the present authors to review the problem of cohesion forces in kaolinite. Structural and spectroscopic criteria as applied to kaolinite proved that the cohesion of adjacent kaolinite layers may be estimated in terms of bent hydrogen bonds. Energy calculations were performed with the aid of a Lennard-Jones function using a modified linear model of the hydrogen bonds. The entire energy is composed of four terms described by the general potential function, van der Waals repulsion and an electrostatic attraction. The energy values of the individual terms are within the limits characteristic of each of them.

Qualitative and Quantitative Study of Stacking Faults in a Hydrazine Treated Kaolinite—Relationship with the Infrared Spectra

“…Since the thickness of the original crystallite is reduced statistically by a factor of two, the treatment has broken the cohesion between the layers. If this cohesion was identical for all the layers within a crystallite, the cleavage energy could reach 20 kcal/g unit cell (Wieckowski and Wiewiora, 1976) and perhaps 30 kcal/g unit cell (Cruz et al, 1972). Obviously the (a) effect demands a lower energy than the (b) effect.…”

Hydroxyl Deformation in Kaolins

“…As a consequence, more non-hydrogen-bonded hydroxyl groups would be found, resulting an increase in the intensity of the 890-895 cm 1 region. The hydroxyl stretching and deformation vibrational modes have been shown to strongly correlate with the degree of disorder (Barrios et al 1977) and interlayer bonding (Wieckowski and Wiewi6ra 1976;Giese 1988;Johnston and Stone 1990). The variation in the hydroxyl deformation modes reported in Table 1 may be due to differences in crystallinity and hydrogen bonding among the kaolinites.…”

Influence of Hydrazine on the Vibrational Modes of Kaolinite

“…Unlike the broad, poorly resolved OH-stretching bands associated with many 2:1 layer silicates, the five distinct IR-and Raman-active OH-stretching bands of kaolinite are well-resolved and are sensitive to subtle changes in their local environment. Shifts in the position, bandwidth, and relative intensities of the inner-surface-OH-stretching (v(O-H)) bands of kaolinite reflect changes which occur in the interlamellar environment, and perturbations of these structural v(O-H) bands of kaolinite have been used to obtain information about the degree of structural disorder (Barrios et al, 1977;Brindley et aL, 1986), dehydration-dehydroxylation processes (Fripiat and Toussaint, 1963;White et al, 1970;Costanzo and Giese, 1985), the nature of interlayer bonding (Wieckowski and Wiewiora, 1976;Wiewiora et aL, 1979), and the structure and bonding of guest species in the interlayer region Johnston et al, 1984;Thompson and Cuff, 1985;Raupach et al, 1987).…”