Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-23T16:24:16.327Z Has data issue: false hasContentIssue false

Differing effects of particle size and shape in the infrared and Raman spectra of kaolinite

Published online by Cambridge University Press:  09 July 2018

V. C. Farmer*
Affiliation:
Soil Science Group, Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15 8QH, UK

Abstract

Infrared (IR) spectra of well-ordered kaolinites generally show four OH-stretching frequencies, near 3697, 3670, 3652 and 3620 cm-1. Raman spectra of the same kaolinites mostly show an additional band near 3686 cm-1, which, in the coarsely crystalline Keokuk kaolinite, largely replaces the 3695 cm-1 band. It is shown that the 3686 cm-1 band can be ascribed to a transverse optical crystal vibration involving the in-phase stretching vibration of the three inner-surface hydroxyl groups in the unit-cell. Raman exciting radiation, commonly of wavelength near 500 nm, can excite this crystal vibration in crystals of comparable and greater thickness.

Infrared studies are usually made on clay-size (<2 μm) particles, which have mean thicknesses of 30-150 nm. Infrared radiation of wavelength near 2.7 <m can only excite whole crystal vibrations perpendicular to the plates. The in-phase vibration of inner-surface OH groups in the whole-crystal mode lies at 3697 cm-1, which is the same frequency as that of the longitudinal optical mode in macroscopic crystals.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1998

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bish, D.L. (1993) Rietveld refinement of the kaolinite structure at 1.5 K. Clays Clay Miner. 41, 738744.CrossRefGoogle Scholar
Farmer, V.C. (1974) The layer silicates. Pp. 331-363 in: The lnJrared Spectra of Minerals (Farmer, V.C., editor). Mineralogical Society, London.CrossRefGoogle Scholar
Farmer, V.C. & Russell, J.D. (1964) The infrared spectra of layer silicates. Spectrochim. Acta, 20, 11491173.CrossRefGoogle Scholar
Farmer, V.C. & Russell, J.D. (1966) Effects of particle size and structure on the vibrational frequencies of layer silicates. Spectrochim. Acta, 22, 389-398.Google Scholar
Frost, R.L. (1995) Fourier transform Raman spectroscopy of kaolinite, dickite and halioysite. Clays Clay Miner. 43, 191195.CrossRefGoogle Scholar
Frost, R.L. & Van der Gaast, S.J. (1997) Kaolinite hydroxyls–a Raman microscopic study. Clay Miner. 32, 471484.CrossRefGoogle Scholar
Frost, R.L., Fredericks, P.M. & Schurvell H,F. (1996) Raman microscopy of some kaolinite clay minerals. Can. J. AppL Spectrosc. 41, 1014.Google Scholar
Gilson, T.R. & Hendra, P.J. (1970) Laser Raman Spectroscopy. Wiley-Interscience, London.Google Scholar
Hadni, A. (1974) The interaction of infrared radiation with crystals. Pp, 27-67 in: The lnJkared Spectra of Minerals (Farmer, V.C., editor). Mineralogical Society, London.Google Scholar
Johnston, C.T. & Stone, D.A. (1990) Influence of hydrazine on the vibrational modes of kaolinite. Clays Clay Miner. 38, 121128.CrossRefGoogle Scholar
Johnston, C.T., Sposito, G. & Birge, R.R. (1985) Raman spectroscopic study of kaolinite in aqueous suspension. Clays Clay Miner. 33, 483489.CrossRefGoogle Scholar
Lombardi, G., Russell, J.D. & Keller, W.D. (1987) Compositional and structural variations in the size fractions of a sedimentary and a hydrothermal kaolin. Clays Clay Miner. 35, 321335.CrossRefGoogle Scholar
Michaelian, K.H. (1986) The Raman spectrum of kaolinite #9 at 21°. Can. J. Chem, 64, 285289.CrossRefGoogle Scholar
Nadeau, P.H. (1987) Relationships between the mean area, volume and thickness for dispersed particles of kaolinites and micaceous clays. Clay Miner. 22, 351356.CrossRefGoogle Scholar
Pajcini, V. & Dhamelincourt, P. (1994) Raman study of OH-stretching vibrations in kaolinite at low temperature. AppL Spectrosc. 48, 638641.CrossRefGoogle Scholar
Rouxhet, P.G., Samudacheata, N., Jacobs, H. & Anton, O. (1977) Attribution of the OH stretching bands of kaolinite. Clay Miner. 12, 171179CrossRefGoogle Scholar
Russell, J.D. & Fraser, A.R. (1994) Infrared methods. Pp. 11 –67 in: Clay Mineralogy: Spectroscopic and Chemical Determinative Methods (Wilson, M.J., editor). Chapman & Hall, London.Google Scholar
Russell, J.D., McHardy, W.J. & Fraser, A.R. (1969) Imogolite: a unique aluminosilicate. Clay Miner. 8, 8799.CrossRefGoogle Scholar
Shoval, S., Boudeulle, M. & Panczer, G. (1995) Raman micro-spectrometry and infrared spectroscopy study of the alteration products of trachyte sills and dykes in Makhtesh Raman area, Israel. Pp. 325–327 in: Physics and Chemistry of Dykes (Baer, G. & Heimann, A., editors). Balkema, Rotterdam.Google Scholar
Wiewiora, A., Wieckowski, T. & Sokolowska, A. (1979) The Raman spectra of kaolinite sub-group minerals and of pyrophyllite. Arch, Mineral. 35, 5–14.Google Scholar