Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-28T04:37:33.876Z Has data issue: false hasContentIssue false

Structural Changes of Allophane During Purification Procedures as Determined by Solid-State 27Al and 29Si NMR

Published online by Cambridge University Press:  01 January 2024

Syuntaro Hiradate*
Affiliation:
Department of Biological Safety Science, National Institute for Agro-Environmental Sciences (NIAES), 3-1-3 Kan-nondai, Tsukuba, Ibaraki 305-8604, Japan
*
*E-mail address of corresponding author: [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Allophanes are poorly crystalline and quasi-stable aluminosilicate minerals, the structures of which are sensitive to chemical treatment. In the present study, solid-state 27Al and 29Si nuclear magnetic resonance (NMR) spectra of allophane samples were monitored as they went through several purification procedures. It was confirmed that no significant structural changes were caused by boiling with 6% H2O2 to remove organic matter, by size fractionation (sonification), by sedimentation, by precipitation at pH 4.0, or by dithionite-citrate-bicarbonate treatment for the removal of Fe (hydr)oxides. Hot 5% Na2CO3 treatment for the removal of reactive silica-alumina gels and adsorbed citrate from allophane samples, however, decreased signal intensity corresponding to imogolite-like Si (Q33VIAl, −78 ppm in 29Si NMR) and increased signal intensities corresponding to IVAl (55 ppm in 27Al NMR) and possibly X-ray amorphous aluminosilicates (centered at −85 ppm in 29Si NMR). Cold (room temperature) 5% Na2CO3 treatment for 16 h proved to be effective in avoiding these structural changes.

Type
Research Article
Copyright
Copyright © 2005, The Clay Minerals Society

References

Childs, C.W. Parfitt, R.L. and Newman, R.H., (1990) Structural studies of Silica Springs allophane Clay Minerals 25 329341 10.1180/claymin.1990.025.3.08.CrossRefGoogle Scholar
Childs, C.W. Hayashi, S. and Newman, R.H., (1999) Five-coordinate aluminum in allophane Clays and Clay Minerals 47 6469 10.1346/CCMN.1999.0470107.CrossRefGoogle Scholar
FAO, World Reference Base for Soil Resources (1998).Google Scholar
Farmer, V.C. Smith, B.F.L. and Tait, J.M., (1977) Alteration of allophane and imogolite by alkaline digestion Clay Minerals 12 195198 10.1180/claymin.1977.012.3.02.CrossRefGoogle Scholar
Ghoneim, A.M. Matsue, N. and Henmi, T., (2001) Zinc adsorption on nano-ball allophanes with different Si/Al ratios Clay Science 11 337348.Google Scholar
Harsh, J. Chorover, J. Nizeyimana, E., Dixon, J.B. and Schulze, D.G., (2002) Allophane and imogolite Soil Mineralogy with Environmental Applications Madison, Wisconsin Soil Science Society of America 291322.Google Scholar
Henmi, T., (1988) Mode of the presence for the SiO4 tetrahedra in the structure of allophanes Japanese Journal of Soil Science and Plant Nutrition 59 237241.Google Scholar
Hiradate, S., (2004) Speciation of aluminum in soil environments: application of NMR technique Soil Science and Plant Nutrition 50 303314 10.1080/00380768.2004.10408483.CrossRefGoogle Scholar
Hiradate, S. and Wada, S.-I., (2005) Weathering process of volcanic glass to allophane determined by 27Al and 29Si solid-state NMR Clays and Clay Minerals 53 401408 10.1346/CCMN.2005.0530408.CrossRefGoogle Scholar
Hu, J. Kannangara, G.S.K. Wilson, M.A. and Reddy, N., (2004) The fused silicate route to protoimogolite and imogolite Journal of Non-crystalline Solids 347 224230 10.1016/j.jnoncrysol.2004.08.237.CrossRefGoogle Scholar
Ildefonse, P. Kirkpatrick, R.J. Montez, B. Calas, G. Flank, A.M. and Lagarde, P., (1994) 27Al MAS NMR and aluminum X-ray absorption near edge structure study of imogolite and allophanes Clays and Clay Minerals 42 276287 10.1346/CCMN.1994.0420306.CrossRefGoogle Scholar
MacKenzie, K.J.D. Bowden, M.E. and Meinhold, R.H., (1991) The structure and thermal transformations of allophanes studied by 29Si and 27Al high resolution solid-state NMR Clays Clay Minerals 39 337346 10.1346/CCMN.1991.0390401.CrossRefGoogle Scholar
Mehra, O.P. and Jackson, M.L., (1960) Iron oxide removal from soils and clays by dithionite-citrate system buffered with sodium bicarbonate Clays and Clay Minerals 7 317327 10.1346/CCMN.1958.0070122.CrossRefGoogle Scholar
Padilla, G.N. Matsue, N. and Henmi, T., (2002) Change in surface properties of nano-ball allophane as influenced by sulfate adsorption Clay Science 12 3339.Google Scholar
Soil Survey Staff, Key to Soil Taxonomy (1999) 8th edition. Blacksburg, Virginia Soil Conservation Service/USDA/Pocahontas Press.Google Scholar
Wada, K., (1986) Ando Soils in Japan Fukuoka, Japan Kyushu University Press.Google Scholar
Wada, K., Dixon, J.B. and Weed, S.B., (1989) Allophane and imogolite Minerals in Soil Environments 2nd edition Madison, Wisconsin Soil Science Society of America 10511087.Google Scholar
Wilson, M.A., (1987) N.M.R. Techniques and Applications in Geochemistry and Soil Chemistry Oxford, UK. Pergamon Press.Google Scholar
Yoshinaga, N. Nakai, M. and Yamaguchi, M., (1973) Unusual accumulation of gibbsite and halloysite in the Kitakami pumice bed, with a note on their genesis Clay Science 4 155165.Google Scholar