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Small-Angle X-Ray Powder Diffraction, Morphology, and Structure of Allophane and Imogolite

Published online by Cambridge University Press:  02 April 2024

S. J. van der Gaast ,
K. Wada ,
S.-I. Wada  and
Y. Kakuto
S. J. van der Gaast
Affiliation:
Netherlands Institute for Sea Research, P.O. Box 59, Texel, The Netherlands
K. Wada
Affiliation:
Faculty of Agriculture, Kyushu University 46, Fukuoka 812, Japan
S.-I. Wada
Affiliation:
Faculty of Agriculture, Kyushu University 46, Fukuoka 812, Japan
Y. Kakuto
Affiliation:
Faculty of Agriculture, Kyushu University 46, Fukuoka 812, Japan
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Abstract

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Small-angle X-ray powder diffraction analyses and high-resolution electron microscopy of allophane samples (SiO2/Al2O3 ratio, 1.12 to 1.68) showed that allophanes consist of nearly identical spherical particles with diameters of about 40 Å and retain their characteristic “hollow” spherical morphology at different ambient moisture and even after dehydroxylation by heating at 500° to 600°C. Unheated allophane samples gave another X-ray powder diffraction band whose maximum position varied from 12.3 to 14.5 A depending on their SiO2/Al2O3 ratio. The appearance of this band may denote some long-range ordering in the structure of allophane. Unlike the spherical particles of allophane, the tube unit of imogolite collapsed on dehydroxylation. This observation suggests that imogolite and allophane are different in their framework structures and that a Si- or Si(Al)-tetrahedral sheet rather than an Al-octahedral sheet constitutes the framework structure of allophane, irrespective of its SiO2/Al2O3 ratio.

Keywords

AllophaneDehydroxylationImogoliteInfrared spectroscopyMorphologySmall angle scattering
Type
Research Article
Information
Clays and Clay Minerals , Volume 33 , Issue 3 , June 1985 , pp. 237 - 243
Copyright
Copyright © 1985, The Clay Minerals Society

References

Barron, P. F., Wilson, M. A., Campbell, A. S. and Frost, R. L., 1982 Detection of imogolite in soils using solid state 29Si NMR Nature 299 616–618.CrossRefGoogle Scholar
Brindley, G. W. and Nakahira, M., 1959 The kaolinite-mullite reaction series. II. Metakaolin J. Amer. Ceram. Soc 42 314–318.CrossRefGoogle Scholar
Brown, G., Brindley, G. W. and Brown, G., 1980 Associated minerals Crystal Structures of Clay Minerals and Their X-ray Identification London Mineralogical Society 361–410.CrossRefGoogle Scholar
Cradwick, P. D. G., Farmer, V. C., Russell, J. D., Masson, C. R., Wada, K. and Yoshinaga, N., 1972 Imogolite, a hydrated aluminum silicate of tubular structure Nature 240 187–189.Google Scholar
Egashira, K. and Aomine, S., 1974 Effects of drying and heating of the surface area of allophane and imogolite Clay Sci 4 231–242.Google Scholar
Farmer, V. C., Fraser, A. R., Mortland, M. M. and Farmer, V. C., 1979 Synthetic imogolite, a tubular hydroxyaluminum silicate Proc. Int. Clay Conf., Oxford, 1978 Amsterdam Elsevier 547–553.Google Scholar
Guinier, A., 1963 X-ray Diffraction in Crystals, Imperfect Crystals and Amorphous Bodies 340–342.Google Scholar
Henmi, T., Tange, K., Minagawa, T. and Yoshinaga, N., 1981 Effect of SiO2/R2O3 ratio on the thermal reactions of allophane. II. Infrared and X-ray powder diffraction data Clays & Clay Minerals 29 124–128.CrossRefGoogle Scholar
Henmi, T. and Wada, K., 1976 Morphology and composition of allophane Amer. Mineral 61 379–390.Google Scholar
Kitagawa, Y., 1971 The “unit particle” of allophane Amer. Mineral 56 465–475.Google Scholar
Kitagawa, Y., 1974 Dehydration of allophane and its structural formula Amer. Mineral 59 1094–1098.Google Scholar
MacEwan, D. M. C., Ruiz, A. A., Brown, G. and Brown, G., 1961 Interstratified clay minerals The X-ray Identification and Crystal Structure of Clay Minerals London Mineralogical Society 393–445.Google Scholar
Parfitt, R. L., Furkert, R. J. and Henmi, T., 1980 Identification and structure of two types of allophane from volcanic ash soils and tephra Clays & Clay Minerals 28 328–334.CrossRefGoogle Scholar
Parfitt, R. L. and Henmi, T., 1980 Structure of some allophanes from New Zealand Clays & Clay Minerals 28 285–294.CrossRefGoogle Scholar
Vainshtein, B. K., 1966 Diffraction of X-ray by Chain Molecules Amsterdam Elsevier 328–334.Google Scholar
van der Gaast, S. J. and Vaars, A. J., 1981 A method to eliminate the background in X-ray diffraction patterns of oriented clay mineral samples Clay Miner 16 383–393.CrossRefGoogle Scholar
Wada, K., Mortland, M. M. and Farmer, V. C., 1979 Structural formulas of allophanes Proc. Int. Clay Conf, Oxford, 1978 Amsterdam Elsevier 537–545.Google Scholar
Wada, K. and Yoshinaga, N., 1969 The structure of “imogolite” Amer. Mineral 54 50–71.Google Scholar
Wada, K., Yoshinaga, N., Yotsumoto, H., Ibe, K. and Aida, S., 1970 High resolution electron micrographs of imogolite Clay Miner 8 487–489.CrossRefGoogle Scholar
Wada, S. and Wada, K., 1977 Density and structure of allophane Clay Miner 12 289–298.CrossRefGoogle Scholar
Wilson, M. A., Barron, P. F. and Campbell, A. S., 1984 Detection of aluminum coordination in soils and clay fractions using 27Al magic angle spinning n.m.r. J. Soil Sci 35 201–207.CrossRefGoogle Scholar
Yoshinaga, N. and Aomine, S., 1962 Imogolite in some Ando soils Soil Sci. Plant Nutr 8 22–29.CrossRefGoogle Scholar