Hostname: page-component-848d4c4894-xm8r8 Total loading time: 0 Render date: 2024-07-07T00:52:29.413Z Has data issue: false hasContentIssue false

Nanometer-scale chemical modification of nano-ball allophane

Published online by Cambridge University Press:  01 January 2024

Zaenal Abidin
Affiliation:
Applied Chemistry for Environmental Industry Laboratory, Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566, Japan Inorganic Chemistry Laboratory, Department of Chemistry, Faculty of Mathematics and Natural Science, Bogor Agricultural University, Kampus IPB Darmaga Jl. Meranti Bogor, West of Java, 16680 Indonesia
Naoto Matsue
Affiliation:
Applied Chemistry for Environmental Industry Laboratory, Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566, Japan
Teruo Henmi*
Affiliation:
Applied Chemistry for Environmental Industry Laboratory, Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566, Japan
*
*E-mail address of corresponding author: henmi@agr.ehime-u.ac.jp

Abstract

Nano-ball allophane is a hydrous Al silicate with a hollow-sphere morphology that contains some defects or pores along the spherule walls. Enlargement of the pore openings by dilute alkali treatment was confirmed by cation exchange capacity determinations using various alkylammonium cations as replacement cations. An allophane sample with a low Si/Al ratio (0.67) was equilibrated with 10 mM CaCl2 (pH = 6.0) and the Ca2+ retained was extracted using aqueous 1 M NH4C1 or alkylammonium chloride salts. The Ca2+ extracted by NH4+ was 15.1 cmolc kg−1, but CH3NH3+${\rm{C}}{{\rm{H}}_3}{\rm{NH}}_3^ + $ (mean diameter = 0.38 nm) only extracted 7.9 cmolc kg−1 of Ca2+. After 10 mM NaOH treatment (0.25 g:100 mL) of the allophane, the Ca2+ extracted by NH4+${\rm{NH}}_4^ + $ was 29.7 cmolc kg−1, 29.6 cmolc kg−1 by CH3NH3+${\rm{C}}{{\rm{H}}_3}{\rm{NH}}_3^ + $, and 29.4 cmolc kg−1 by (CH3)2NH2+${{\rm{(C}}{{\rm{H}}_3}{\rm{)}}_2}{\rm{NH}}_2^ + $. The extraction of Ca2+ by the large C2H5NH3+${{\rm{C}}_2}{{\rm{H}}_5}{\rm{NH}}_3^ + $ cation (mean diameter = 0.46 nm) only decreased to 26.1 cmolc kg−1, indicating that pore diameters were enlarged from ∼0.35 to 0.45 nm. The significant increase in Ca2+ retention after NaOH treatment was attributed to the dissociation of increased numbers of newly exposed silanol groups in the enlarged pores. The low Si/Al ratio of the NaOH-dissolved material (0.35) and the decreased intensity of the 348 cm−1 IR band also suggested selective dissolution of the pore region. For allophane with a high Si/Al ratio (0.99) and much accessory polymeric Si, dissolution of polymeric Si and of the pore region occurred simultaneously. Alkali treatment produced a smaller increase in pore size and Ca2+ retention for allophanes with large Si/Al ratios than for allophanes with small Si/Al ratios. It was concluded that by altering the dilute alkali treatment conditions and varying the Si/Al ratio of allophane, the extent of structural modification or pore enlargement of the hollow spheres might be controlled.

Type
Research Article
Copyright
Copyright © 2007, The Clay Minerals Society

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

Abidin, Z. Matsue, N. and Henmi, T., (2004) Dissolution mechanism of nano-ball allophane with dilute alkali solution Clay Science 12 213222.Google Scholar
Abidin, Z. Matsue, N. and Henmi, T., (2005) Molecular orbital analysis on the dissolution of nano-ball allophane under alkaline condition Clay Science 13 16.Google Scholar
Abidin, Z. Matsue, N. and Henmi, T., (2006) Validity of proposed model for the chemical structure of allophane with nano-ball morphology Proceedings of the 13th International Clay Conference, Tokyo. Clay Science 12 267269 Supplement 2.Google Scholar
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 Physical Science 240 187189 10.1038/physci240187a0.CrossRefGoogle Scholar
Farmer, V.C. Fraser, A.R. Russell, J.D. and Yoshinaga, N., (1977) Recognition of imogolite structures in allophanic clays by infrared spectroscopy Clay Minerals 12 5557 10.1180/claymin.1977.012.1.04.CrossRefGoogle Scholar
Henmi, T., (1980) Effect of SiO2/Al2O3 ratio on thermal reactions of allophane Clays and Clay Minerals 28 9296 10.1346/CCMN.1980.0280203.CrossRefGoogle Scholar
Henmi, T. (1985) Importance of chemical composition (SiO2/A12O3 ratio) as factor affecting physicochemical properties of allophane from weathered volcanic ash and pumice. 5thMeeting of European Clay Groups, pp. 459464.Google Scholar
Henmi, I. Matsue, N. and Henmi, T., (2001) Effect of acid species and co-existing anions on the dissolution of Al and Si from allophane by treatment of diluted acid solutions Journal of Clay Science Society Japan 2 5863 (in Japanese with English abstract).Google Scholar
Henmi, T. and Wada, K., (1976) Morphology and composition of allophane American Mineralogist 61 379390.Google Scholar
Higashi, T. and Ikeda, H., (1974) Dissolution of allophane by acid oxalate solution Clay Science 4 205212.Google Scholar
Khan, H. Matsue, N. and Henmi, T., (2006) Adsorption of water on nano-ball allophane Proceedings of the 13th International Clay Conference, Tokyo. Clay Science 12 261266 Supplement 2.Google Scholar
Matsue, N. and Henmi, T., (1993) Molecular orbital study on the relationship between Si/Al ratio and surface acid strength of allophane Journal of Clay Science Society Japan 33 102106 (in Japanese with English abstract).Google Scholar
Mitchell, B.D. Farmer, V.C. and McHardy, W.J., (1964) Amorphous inorganic materials in soils Advances in Agronomy 16 327383 10.1016/S0065-2113(08)60028-0.CrossRefGoogle Scholar
Nartey, E. Matsue, N. and Henmi, T., (2001) Charge characteristics modification mechanisms of nano-ball allophane upon orthosilicic acid adsorption Clay Science 11 465478.Google Scholar
Parfitt, R.L. and Henmi, T., (1980) Structure of some allophane from New Zealand Clays and Clay Minerals 28 285294 10.1346/CCMN.1980.0280407.CrossRefGoogle 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 and Clay Minerals 28 328334 10.1346/CCMN.1980.0280502.CrossRefGoogle Scholar
Parfitt, R.L. and Kimble, J.M., (1989) Conditions for formation of allophane in soils Soil Science Society of America Journal 53 971977 10.2136/sssaj1989.03615995005300030057x.CrossRefGoogle Scholar
Shimizu, H. Watanabe, T. Henmi, T. Masuda, A. and Saito, A., (1988) Study on allophane and imogolite by high-resolution solid state 29Si- and 27A1-NMR and ESR Geochemical Journal 22 2331 10.2343/geochemj.22.23.CrossRefGoogle Scholar
Wada, S. and Wada, K., (1977) Density and structure of allophane Clay Minerals 12 289298 10.1180/claymin.1977.012.4.02.CrossRefGoogle Scholar
Wada, K., Dixon, J.B. and Weed, S.B., (1989) Allophane and imogolite Minerals in Soil Environments 2 Madison, Wisconsin Soil Science Society of America 10511088.Google Scholar