Abstract
Transmission X-ray diffraction (XRD) of C6–16 alkylammonium ion-exchanged montmorillonite SAz-1 with Ag-behenate as an internal standard provided accurate estimates of d(001) values of the alkylammonium ion-exchanged montmorillonite. Inspection of d(001) values were made to assess the possible formation of gauche conformers (alternate arrangements of the molecules) in the interlayer and to determine the critical carbon chain length, nC. Using conventional constraints for nC(I′) and nC(II) equal to 1.36 and 1.77 nm, respectively, provided ambiguous nC(I′) and nC(II) values. The dependence of full-width at half-maximum values on nC allowed better estimates of nC(I′) and nC(II) because “integral” and “non-integral” peak characteristics relating to interstratification could be included in the assessment.
The effect of inaccurate estimates of nC(I′) and nC(II) values on calculated interlayer cation exchange capacity (Ci) using two conventional concepts of calculation were compared. It was found that a procedure based on the summation of fractions of the layer charge gave relative errors of Ci <2%, even where the number of carbon atoms corresponding to both nC(I′) and nC(II) differed by ± 1 nC from the correct values. This method of calculation of Ci is recommended when reliable values of Ci are needed.
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Beneke, K. and Lagaly, G. (1982) The brittle mica-like KniAsO4 and its organic derivates. Clay Minerals, 17, 175–183.
Blanton, T.N., Huang, T.C., Toraya, H., Hubbard, C.R., Robie, S.B., Louër, D., Göbel, H.E., Will, G., Giles, R., and Raftery, T. (1995) JCPDS-International Centre for Diffraction Data round robin study of silver behenate. A possible low-angle X-ray diffraction calibration standard. Powder Diffraction, 10, 91–95.
Číčel, B. and Komadel, P. (1994) Structural formulae of layer silicates. In Soil Science Society of America Miscellaneous Publication, Quanitative Methods in Soil Mineralogy, J.E. Amoneet and L.W. Zelazny, eds., Madison, Wisconsin, 114–136.
Hall, M.M., Veeraraghavan, V.G., Rubin, H., and Winchell, P.G. (1977) The approximation of symmetric X-ray peaks by Pearson type VII distributions. Journal of Applied Crystallography, 10, 66–68.
Janek, M., Komadel, P., and Lagaly, G. (1997) Effect of autotransformation on the layer charge of smectites determined by alkylammonium method. Clay Minerals, 32, 623–632.
Kelley, W.P. (1955) Interpretation of chemical analyses of clays. Clays and Clay Minerals, 1, 92–94.
Lagaly, G. (1981) Characterization of clays by organic compounds. Clay Minerals, 16, 1–21.
Lagaly, G. (1994) Layer charge determination by alkylammonium ions. In Clay Minerals Society Workshop Lectures 6, Layer Charge Characteristics of 2:1 Silicate Clay Minerals, A.R. Mermut, ed., Boulder, Colorado, 1–46.
Lagaly, G. and Beneke, K. (1991) Intercalation and exchange reactions of clay minerals and non-clay layer compounds. Colloid Polymer Science, 269, 1198–1211.
Lagaly, G. and Weiss, A. (1969) Determination of the layer charge in mica-type layer silicates. Proceedings of the International Clay Conference, Tokyo, 1969, I, 61–80.
Lagaly, G. and Weiss, A. (1971) Neue Methoden zur Char-akterisierung und Idenifizierung quellungsfàhiger Dreis-chichttonminerale. Zeitshcrift Pflanzenern Bodenkunde, 130, 9–24.
Lagaly, G. and Weiss, A. (1975) The layer charge of smectitic layer silicates. Proceedings of the International Clay Conference, Mexico. Applied Publishing Ltd, Wilmette, Illinois, 157–172.
Lagaly, G., Fernandez Gonzales, M., and Weiss, A. (1976) Problems in layer-charge determination of montmorillon-ites. Clay Minerals, 11, 173–187.
Laird, D.A. (1994) Evaluation of structural formulae and alkylammonium method of determining layer charge. In Clay Minerals Society Workshop Lectures 6, Layer Charge Characteristics of 2: 1 Silicate Clay Minerals, A.R. Mermut, ed., Boulder, Colorado, 79–104.
Laird, D.A., Scott, A.D., and Fenton, T.E. (1987) Interpretation of alkylammonium characterization of soil clays. Soil Science Society of America Journal, 51, 1659–1663.
Laird, D.A., Scott, A.D., and Fenton, T.E. (1989) Evaluation of the alkylammonium method of determining layer charge. Clays and Clay Minerals, 37, 41–46.
MacEwan, D.M.C., Ruiz Amil, A., and Brown, G. (1961) Interstratified clay minerals. In The X-ray Identification and Crystal Structures of Clay Minerals, G. Brown, ed., Mineralogical Society, London, 393–445.
Maes, A., Stul, M.S., and Cremers, A. (1979) Layer charge—cation-exchange capacity relationships in montmorillonite. Clays and Clay Minerals, 27, 387–392.
Malla, P.B. and Lowell, A.D. (1987) Layer charge properties of smectites and vermiculites: Tetrahdral vs octahedral. Soil Science Society of America Journal, 51, 1362–1366.
Mermut, A.R. (1994) Problems associated with layer charge characterization of 2:1 phyllosilicates. In Clay Minerals Society Workshop Lectures 6, Layer Charge Characteristics of 2:1 Silicate Clay Minerals, A.R. Mermut, ed., Boulder, Colorado, 105–127.
Reynolds, R.C. (1980) Interstratified clay minerals. In Crystal Structures of Clay Minerals and Their X-ray Identification, G.W. Brindley and G. Brown, eds., Mineralogical Society, London, 249–303.
Ruehlicke, G. and Kohier, E.E. (1981) A simplified procedure for determining layer charge by the n-alkylammonium method. Clay Minerals, 16, 305–307.
Stanjek, H., Niederbudde, E.A., and Häusler, W. (1992) Improved evaluation of layer charge of n-alkylammonium-treated fine soil clays by Lorenz- and polarization-correction and curve-fitting. Clay Minerals, 27, 3–19.
Vaia, R.A., Teukolsky, R.K., and Giannelis, E.P. (1994) Interlayer structure and molecular environment of alkylam-monium layered silicates. Chemical Materials, 6, 1017–1022.
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Janek, M., Smrčok, L. Application of an Internal Standard Technique by Transmission X-Ray Diffraction to Assess Layer Charge of a Montmorillonite by Using the Alkylammonium Method. Clays Clay Miner. 47, 113–118 (1999). https://doi.org/10.1346/CCMN.1999.0470201
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DOI: https://doi.org/10.1346/CCMN.1999.0470201