Abstract
Imogolite was synthesized at 25°C by aging partially neutralized solutions containing monomeric silicic acid and polymeric hydroxy-aluminum ions for 7 years. Solutions having an initial Si/Al molar ratio of about 0.5 and pHs of 4.0–4.5 produced the largest yields of imogolite, followed by those having an initial Si/Al ratio of about 1, although imogolite was not the principal product. Electron microscopic examination showed a small amount of imogolite fibers embedded in a noncrystalline gel-like substance. Traces of imogolite were detected in solutions having an initial Si/Al ratio of about 2, but no imogolite was found by electron microscopy in products from solutions having an initial Si/Al ratio of about 4. Only gibbsite formed from solutions having initial Si/Al ratios of <0.27. The diameter of the tubular structural unit of the imogolite produced in these experiments was 23 ± 2Å, close to that of natural imogolite.
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References
Chesworth, W. (1972) The stability of gibbsite and boemite at the surface of the earth: Clays & Clay Minerals, 20, 369–374.
Cradwick, P. D. G., Farmer, V. C., Russell, J. D., Masson, C. R., Wada, K., and Yoshinaga, N. (1972) Imogolite, a hydrated aluminium silicate of tubular structure: Nature Phys. Sci. 240, 187–189.
Farmer, V. C., Fraser, A. R., and Tait, J. M. (1977) Synthesis of imogolite: A tubular aluminium silicate polymer: J. Chem. Soc. Chem. Comm. 13, 462–463.
Farmer, V. C. and Fraser, A. R. (1978) Synthetic imogolite, a tubular hydroxyaluminium silicate: in Proc. Int. Clay Conf., Oxford, 1978, M. M. Mortland and V. C. Farmer, eds., Elsevier, Amsterdam, 547–553.
Farmer, V. C. and Fraser, A. R. (1982) Chemical and colloidal stability of sols in the Al2O3-Fe2O3-SiO2-H2O system: Their role in podzolization: J. Soil Sci. 33, 733–742.
Farmer, V. C., Smith, B. F. L., and Tait, J. M. (1979) The stability, free energy and heat of formation of imogolite: Clay Miner. 14, 103–107.
Henmi, T. and Wada, K. (1976) Morphology and composition of allophane: Amer. Mineral. 61, 379–390.
Inoue, K. and Huang, P. M. (1985) Influence of citric acid on the formation of short-range ordered aluminosilicates: Clays & Clay Minerals 33, 312–322.
Kitagawa, Y. (1971) The “unit particle” of allophane: A mer. Mineral. 56, 465–475.
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.
Singh, S. S. (1974) The solubility product of gibbsite at 15, 25, and 35°C: Soil Sci. Soc. Amer. Proc. 38, 415–417.
Tait, J. M., Yoshinaga, N., and Mitchell, B. D. (1978) The occurrence of imogolite in some Scottish soils: Soil Sci. Plant Nutr. 24, 145–151.
Wada, K., Henmi, T., Yoshinaga, N., and Patterson, S. H. (1972) Imogolite and allophane formed in saprolite of basalt on Maui, Hawaii: Clays & Clay Minerals 20, 375–380.
Wada, S.-I. (1986) Modification of 8-quinolinolate extraction method for determination of monomelic aluminum ions: Jap. J. Soil Sci. Plant Nutr. 57, 506–508 (in Japanese).
Wada, S.-I., Eto, A., and Wada, K. (1979) Synthetic allophane and imogolite: J. Soil Sci. 30, 347–355.
Wada, S.-I. and Wada, K. (1980) Composition and structure of hydroxy-aluminosilicate ions: J. Soil Sci. 31, 457–467.
Wada, S.-I. and Wada, K. (1982) Effect of substitution of germanium for silicon in imogolite: Clays & Clay Minerals 30, 123–128.
Yoshinaga, N., Nakai, M., Minagawa, T., and Henmi, T. (1984) Formation of imogolite and allophane in shattered sandstone underlying brown forest soil: Soil Sci. Plant Nutr. 30, 555–567.
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Wada, Si. Imogolite Synthesis at 25°C. Clays Clay Miner. 35, 379–384 (1987). https://doi.org/10.1346/CCMN.1987.0350508
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DOI: https://doi.org/10.1346/CCMN.1987.0350508