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Characterization of Intercalated Smectites Using XRD Profile Analysis in the Low-Angle Region

Published online by Cambridge University Press:  28 February 2024

Daniel Janeba
Affiliation:
Faculty of Mathematics and Physics, Charles University Prague, Ke Karlovu 5, 121 16 Prague, Czech Republic
Pavla Čapková
Affiliation:
Faculty of Mathematics and Physics, Charles University Prague, Ke Karlovu 5, 121 16 Prague, Czech Republic
Zdeněk Weiss
Affiliation:
Central Analytical Laboratory, Technical University of Mining and Metallurgy, 708 33 Ostrava, Czech Republic
Henk Schenk
Affiliation:
Laboratory of Crystallography, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands

Abstract

X-ray diffraction (XRD) characterization of natural and intercalated smectites is usually limited to the apparent d-value estimated from the peak maxima in the raw data. This can lead to the misinterpretation of the measured data. In the case of XRD, the interference function is modulated by instrumental factors (Lorentz-polarization factor, diffraction geometry) and physical factors (structure factor, surface roughness effect). These effects lead to diffraction profile distortions, depending on the diffraction angle and peak full width at half maximum (FWHM). As a result, the diffraction profiles for structures with large line broadening (FWHM > 1°) exhibit a significant peak shift (Δd ∼ 1.5 Å), especially at low angles (2θ ≤ 10°). The present work deals with the detailed analysis of all these effects, their corrections and their consequences for the interpretation of diffraction patterns (including possible errors in determining lattice parameters or the structure model). The investigated materials were montmorillonites (MMT) intercalated with hydroxy-Al polymers. Diffraction profile analysis revealed the corrected d-values and showed that the intercalated sample is not a mixed-layered structure. As a result a structural model of the interlayer is presented.

Type
Research Article
Copyright
Copyright © 1998, The Clay Minerals Society

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References

Čapková, P. Driessen, R.A.J. Numan, M. Schenk, H. Weiss, Z. and Klika, Z., 1998 Molecular simulations of the montmorillo-nite intercalated with aluminium complex cations Parts I and II. Clays Clay Miner .Google Scholar
Figueras, F. Klapyta, Z. Massiani, P. Mountassir, Z. Tichit, D. Fajula, F. Gueguen, C. Bousquet, J. and Auroux, A., 1990 Use of competetive ion exchange for intercalation of montmoril-lonite with hydroxy-aluminium species Clays Clay Miner 38 257264 10.1346/CCMN.1990.0380304.CrossRefGoogle Scholar
Hsu, P.H., 1992 Reaction of OH-A1 polymers with smectites and vermiculites Clays Clay Miner 40 300305 10.1346/CCMN.1992.0400308.CrossRefGoogle Scholar
Ibers, J.A. and Hamilton, W.C., 1974 International tables for X-ray crystallography, Vol. IV—Revised and supplementary tables Birmingham Kynoch Pr..Google Scholar
Johansson, G., 1962 The crystal structures of [Al2(OH)2(H2O)8] (SO4)2· 2H2O and [Al2(OH)2(H2O)8](SeO4)2·2H2O Acta Chem Scand 16 403420 10.3891/acta.chem.scand.16-0403.CrossRefGoogle Scholar
Klug, H.P. and Alexander, L.E., 1974 X-ray diffraction procedures for polycrystalline and amorphous materials New York Wiley Intersci Publ..Google Scholar
Kužzel, R., 1990 Difpatan [computer program], Faculty of Math and Physics, Charles Univ, Prague, Czech Republic .Google Scholar
Mitchell, W.I., 1990 Pillared layered structures London Elsevier.Google Scholar
Rafaja, D., 1988 Simul [computer program], Faculty of Math and Physics, Charles Univ, Prague, Czech Republic .Google Scholar
Reynolds, R.C., Brindley, G.W. and Brown, G., 1980 Interstratified clay minerals Crystal structures of clay minerals and their X-ray identification London Mineral Soc..Google Scholar
Seul, M. and Torney, D.C., 1989 Statistical theory of X-ray scattering from crystals of finite size with pure displacement disorder in one dimension Acta Crystallogr A45 381396 10.1107/S010876738900098X.CrossRefGoogle Scholar