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Effects of Exchanged Cation on the Microporosity of Montmorillonite

Published online by Cambridge University Press:  28 February 2024

David W. Rutherford ,
Cary T. Chiou  and
Dennis D. Eberl
David W. Rutherford
Affiliation:
US Geological Survey, Box 25046, MS 408, Denver Federal Center, Denver, Colorado 80225
Cary T. Chiou
Affiliation:
US Geological Survey, Box 25046, MS 408, Denver Federal Center, Denver, Colorado 80225
Dennis D. Eberl
Affiliation:
US Geological Survey, 3215 Marine Street, Boulder, Colorado 80303
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Abstract

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The micropore volumes of 2 montmorillonites (SAz-1 and SWy-1), each exchanged with Ca, Na, K, Cs and tetramethylammonium (TMA) ions, were calculated from the measured vapor adsorption data of N2 and neo-hexane by use of t- and αs-plots. The corresponding surface areas of the exchanged clays were determined from Brunauer-Emmett-Teller (BET) plots of N2 adsorption data. Micropore volumes and surface areas of the samples increased with the size of exchanged cation: TMA > Cs > K > Ca > Na. The SAz-1 exchanged clays showed generally greater micropore volumes and surface areas than the corresponding SWy-1 clays. The vapor adsorption data and d(001) measurements for dry clay samples were used together to evaluate the likely locations and accessibility of clay micropores, especially the relative accessibility of their interlayer spacing. For both source clays exchanged with Na, Ca and K ions, the interlayer spacing appeared to be too small to admit nonpolar gases and the accessible micropores appeared to have dimensions greater than 5.0 Å, the limiting molecular dimension of neo-hexane. In these systems, there was a good consistency of micropore volumes detected by N2 and neo-hexane. When the clays were intercalated with relatively large cations (TMA and possibly Cs), the large layer expansion created additional microporosity, which was more readily accessible to small N2 than to relatively large neo-hexane. Hence, the micropore volume as detected by N2 was greater than that detected by neo-hexane. The micropore volumes with pore dimensions greater than 5 Å determined for clays exchanged with Na, Ca and K likely resulted from the pores on particle edges and void created by overlap regions of layers. The increase in micropore volumes with pore dimensions less than 5 Å determined for clays exchanged with TMA and possibly Cs could be caused by opening of the interlayer region by the intercalation of these large cations.

Keywords

Exchanged CationInterlayer AccessibilityMicroporosityMontmorilloniteSurface Area
Type
Research Article
Information
Clays and Clay Minerals , Volume 45 , Issue 4 , August 1997 , pp. 534 - 543
Copyright
Copyright © 1997, The Clay Minerals Society

References

Aylmore, L.A.G. and Quirk, J.P., 1967 The micropore size distribution of clay mineral systems J Soil Sci 18 1–17 10.1111/j.1365-2389.1967.tb01481.x.CrossRefGoogle Scholar
Aylmore, L.A.G. Sills, I.D. and Quirk, J.P., 1970 Surface area of homoionic illite and montmorillonite clay minerals as measured by the sorption of nitrogen and carbon dioxide Clays Clay Miner 18 91–96 10.1346/CCMN.1970.0180204.CrossRefGoogle Scholar
Aylmore, L.A.G. Sills, I.D. and Quirk, J.P., 1970 Reply to comment of Thomas, Bohor and Frost on “The surface area of hom-oionic illite and montmorillonite clay minerals as measured by the sorption of nitrogen and carbon dioxide” Clays Clay Miner 18 407–409 10.1346/CCMN.1970.0180613.CrossRefGoogle Scholar
Brook, C.S., 1955 Nitrogen adsorption experiments on several clay minerals Soil Sci 79 331–347 10.1097/00010694-195505000-00002.CrossRefGoogle Scholar
Brunauer, S. Emmett, P.H. and Teller, E., 1938 Adsorption of gases in multimolecular layers J Am Chem Soc 60 309–319 10.1021/ja01269a023.CrossRefGoogle Scholar
Chiou, C.T. Rutherford, D.W. and Manes, M., 1993 Sorption of N2 and EGME vapors on some soils, clays, and mineral oxides and determination of sample surface areas by use of sorption data Environ Sci Technol 27 1587–1594 10.1021/es00045a014.CrossRefGoogle Scholar
Clementz, D.M. and Mortland, M.M., 1974 Properties of reduced charge montmorillonite: Tetra-alkylammonium ion exchange forms Clays Clay Miner 22 223–229 10.1346/CCMN.1974.0220304.CrossRefGoogle Scholar
de Boer, J.H. Lippens, B.C. Linsen, B.G. Broekhoff, J.C.P. van den Heuvel, A. and Osinga Th, J., 1966 The t-curve of multilayer N2-adsorption J Colloid Interface Sci 21 405–414 10.1016/0095-8522(66)90006-7.CrossRefGoogle Scholar
Eberl, D.D. Śroodoń, J. Northrop, H.R., Davis, J.A. and Hayes, K.F., 1986 Potassium fixation in smectites by wetting and drying Geochemical processes at mineral surfaces, ACS Symp Series 323 Washington, DC Am Chem Soc 296–326.Google Scholar
Gast, R.G. and Mortland, M.M., 1971 Self-diffusion of alkylam-monium ions in montmorillonite J Colloid Interface Sci 37 80–92 10.1016/0021-9797(71)90267-0.CrossRefGoogle Scholar
Gregg, S.J. and Sing, K.S.W., 1982 Adsorption, surface area and porosity 2nd ed. London Academic Pr 61–84.Google Scholar
Lee, J.-F. Mortland, M.M. Chiou, C.T. Kile, D.E. and Boyd, S.A., 1990 Adsorption of benzene, toluene, and xylene by two tetra-methylammonium-smetites having different charge densities Clays Clay Miner 38 113–120 10.1346/CCMN.1990.0380201.CrossRefGoogle Scholar
Mooney, R.W. Keenan, A.G. and Wood, L.A., 1952 Adsorption of water vapor by montmorillonite. I. Heat of desorption and application of BET theory J Am Chem Soc 74 1367–1371 10.1021/ja01126a001.CrossRefGoogle Scholar
van Olphen, H. and Fripiat, J.J., 1979 Data handbook for clay materials and other non-metallic minerals New York Pergamon Pr 16–25.Google Scholar
Remy, M.J. and Poncelet, G., 1995 A new approach to the determination of the external surface and micropore volume of zeolites from the nitrogen adsorption isotherm at 77 K J Phys Chem 99 773–779 10.1021/j100002a047.CrossRefGoogle Scholar
Sing, K.S.W., Everett, D.H. and Ottewill, R.H., 1969 Surface area determination Proc Int. Symp London Buttersworths 25.Google Scholar
Thomas, J. Jr and Bohor, B.F., 1968 Surface area of montmorillonite from the dynamic sorption of nitrogen and carbon dioxide Clays Clay Miner 16 83–91 10.1346/CCMN.1968.0160110.CrossRefGoogle Scholar