Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-10T06:21:31.677Z Has data issue: false hasContentIssue false
  • English
  • Français

Thermodynamics of organic cation exchange selectivity in smectites

Published online by Cambridge University Press:  01 January 2024

Brian J. Teppen  and
Vaneet Aggarwal
Brian J. Teppen*
Affiliation:
Department of Crop and Soil Sciences, Michigan State University, East Lansing, MI 48824-1325, USA
Vaneet Aggarwal
Affiliation:
Department of Crop and Soil Sciences, Michigan State University, East Lansing, MI 48824-1325, USA
*
*E-mail address of corresponding author: teppen@msu.edu
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.

The selectivities of clay minerals for larger organic cations over smaller ones have been attributed to favorable clay-organic interactions in clay interlayers and to hydrophobic effects resulting from (partial) dehydration of organic cations in the clay interlayers, but the magnitudes of these energy components have not been estimated. The objective of this study was to differentiate and quantify the contributions of clay-phase and aqueous-phase energy changes to the overall thermodynamics of cation exchange, and thereby to determine which forces control the general selectivity of smectites for organic cations. We compiled literature measurements and estimates for the free energies of overall cation exchange reactions and also for the free energies of organic cation hydration. Our study suggests that organic cation-exchange thermodynamics can be broken into three classes: (1) For two organic cations with identical head-groups, the difference in their cation exchange selectivities is driven almost quantitatively by the difference in their free energies of hydration. Here, the mechanism for organic cation selectivity is almost pure hydrophobic expulsion of the larger cation from water. The clay interlayer simply behaves like a subaqueous phase into which the least hydrophilic organic cations partition and the essentials of such cation exchange selectivity can be explained without any favorable clay-organic interactions. (2) For two organic cations with rather different head-groups, the difference in their cation exchange selectivities is just a small percentage of the difference in their free energies of hydration. This indicates that the clay phase interacts much more strongly with the cation having the smaller head-group, as might be expected on the basis of simple electrostatics. Here, the clay has an intrinsic strong preference for the cation with smaller head-group yet ‘selects’ for the cation with larger head-group because the aqueous-phase preference for the cation with smaller head-group is even stronger than the clay preference. (3) When the clay is already substantially loaded with organic cations, then van der Waals forces apparently can play a significant role in determining organic cation exchange selectivity differences.

Keywords

Cation ExchangeEnthalpyEntropyFree EnergyHydration EnergySmectitesThermodynamics
Type
Research Article
Information
Clays and Clay Minerals , Volume 55 , Issue 2 , April 2007 , pp. 119 - 130
Copyright
Copyright © 2007, The Clay Minerals Society

References

Abraham, M.H., (1984) Thermodynamics of solution of homologous series of solutes in water Journal of the Chemical Society, Faraday Transactions 80 153–181 10.1039/f19848000153.CrossRefGoogle Scholar
Barrer, R.M., (1989) Clay-minerals as selective and shape-selective sorbents Pure and Applied Chemistry 61 1903–1912 10.1351/pac198961111903.CrossRefGoogle Scholar
Cabani, S. Gianni, P. Mollica, V. and Lepori, L., (1981) Group contributions to the thermodynamic properties of non-ionic organic solutes in dilute aqueous-solution Journal of Solution Chemistry 10 563–595 10.1007/BF00646936.CrossRefGoogle Scholar
Cowan, C.T. and White, D., (1958) The mechanisms of exchange reactions occurring between sodium montmorillonite and various n-primary aliphatic amine salts Transactions of the Faraday Society 54 691–697 10.1039/tf9585400691.CrossRefGoogle Scholar
Florian, J. and Warshel, A., (1997) Langevin dipoles model for ab initio calculations of chemical processes in solution: Parameterization and application to hydration free energies of neutral and ionic solutes and conformational analysis in aqueous solution Journal of Physical Chemistry B 101 5583–5595 10.1021/jp9705075.CrossRefGoogle Scholar
Ford, G.P. and Wang, B.Z., (1992) The optimized ellipsoidal cavity and its application to the self-consistent reaction field calculation of hydration energies of cations and neutral molecules Journal of Computational Chemistry 13 229–239 10.1002/jcc.540130214.CrossRefGoogle Scholar
Fu, M.H. Zhang, Z.Z. and Low, P.F., (1990) Changes in the properties of a montmorillonite system during the adsorption and desorption of water: Hysteresis Clays and Clay Minerals 38 485–492 10.1346/CCMN.1990.0380504.CrossRefGoogle Scholar
Johnston, C.T. and Sawhney, B.L., (1996) Sorption of organic compounds on clay minerals: A surface functional approach Reactions of Organic Pollutants with Clays Bloomington, Indiana The Clay Minerals Society 1–44.Google Scholar
Keren, R. and Shainberg, I., (1980) Water vapor isotherms and heat of immersion of Na- and Ca-montmorillonite systems. III. Thermodynamics Clays and Clay Minerals 28 204–210 10.1346/CCMN.1980.0280306.CrossRefGoogle Scholar
Lagaly, G., (1984) Clay organic interactions Philosophical Transactions of the Royal Society of London Series A — Mathematical, Physical and Engineering Sciences 311 315–332 10.1098/rsta.1984.0031.Google Scholar
Laird, D.A. and Shang, C., (1997) Relationship between cation exchange selectivity and crystalline swelling in expanding 2:1 phyllosilicates Clays and Clay Minerals 45 681–689 10.1346/CCMN.1997.0450507.CrossRefGoogle Scholar
Maes, A. Cremers, A., Davis, J.A. and Hayes, K.F., (1986) Highly selective ion exchange in clay minerals and zeolites Geochemical Processes at Mineral Surfaces Washington, D.C American Chemical Society 254–295 10.1021/bk-1987-0323.ch013.Google Scholar
Maes, A. Marynen, P. and Cremers, A., (1977) Ion-exchange adsorption of alkylammonium ions — alternative view Clays and Clay Minerals 25 309–310 10.1346/CCMN.1977.0250409.CrossRefGoogle Scholar
Maes, A. van Leemput, L. Cremers, A. and Uytterhoeven, J., (1980) Electron-density distribution as a parameter in understanding organic cation-exchange in montmorillonite Journal of Colloid and Interface Science 77 14–20 10.1016/0021-9797(80)90408-7.CrossRefGoogle Scholar
Marcus, Y., (1985) Ion Solvation New York John Wiley & Sons 306 pp.Google Scholar
Marcus, Y., (1997) Ion Properties New York Marcel Dekker 259 pp.Google Scholar
McBride, M.B. and Mortland, M.M., (1975) Surface properties of mixed Cu(II)-tetraalkylammonium montmorillonites Clay Minerals 10 357–368 10.1180/claymin.1975.010.5.03.CrossRefGoogle Scholar
Mizutani, T. Takano, T. and Ogoshi, H., (1995) Selectivity of adsorption of organic ammonium ions onto smectite clays Langmuir 11 880–884 10.1021/la00003a033.CrossRefGoogle Scholar
Mortland, M.M., (1970) Clay-organic complexes and interactions Advances in Agronomy 22 75–117 10.1016/S0065-2113(08)60266-7.CrossRefGoogle Scholar
Nagano, Y. Sakiyama, M. Fujiwara, T. and Kondo, Y., (1988) Thermochemical study of tetramethylammonium and tetra-ethylammonium halides — nonionic cohesive energies in the crystals and hydration enthalpies of the cations Journal of Physical Chemistry 92 5823–5827 10.1021/j100331a054.CrossRefGoogle Scholar
Nagano, Y. Mizuno, H. Sakiyama, M. Fujiwara, T. and Kondo, Y., (1991) Hydration enthalpy of Tetra-Normal-Butylammonium Ion Journal of Physical Chemistry 95 2536–2540 10.1021/j100159a079.CrossRefGoogle Scholar
Pliego, J.R. and Riveros, J.M., (2002) Gibbs energy of solvation of organic ions in aqueous and dimethyl sulfoxide solutions Physical Chemistry Chemical Physics 4 1622–1627 10.1039/b109595a.CrossRefGoogle Scholar
Plyasunov, A.V. and Shock, E.L., (2000) Thermodynamic functions of hydration of hydrocarbons at 298.15 K and 0.1 MPa Geochimica et Cosmochimica Acta 64 439–468 10.1016/S0016-7037(99)00330-0.CrossRefGoogle Scholar
Schmid, R., (2001) Recent advances in the description of the structure of water, the hydrophobic effect, and the like-dissolves-like rule Monatshefte für Chemie 132 1295–1326 10.1007/s007060170019.CrossRefGoogle Scholar
Schwarzenbach, R.P. Gschwend, P.M. and Imboden, D.M., (2003) Environmental Organic Chemistry 2 New York Wiley-Interscience 1000 pp.Google Scholar
Sposito, G. and Prost, R., (1982) Structure of water adsorbed on smectites Chemical Reviews 82 553–573 10.1021/cr00052a001.CrossRefGoogle Scholar
Teppen, B.J. and Miller, D.M., (2006) Hydration energy determines isovalent cation exchange selectivity by clay minerals Soil Science Society of America Journal 70 31–40 10.2136/sssaj2004.0212.CrossRefGoogle Scholar
Theng, B.K.G., (1974) The Chemistry of Clay-Organic Reactions New York John Wiley & Sons 343 pp.Google Scholar
Theng, B.K.G. Greenland, D.J. and Quirk, J.P., (1967) Adsorption of alkylammonium cations by montmorillonite Clay Minerals 7 1–17 10.1180/claymin.1967.007.1.01.CrossRefGoogle Scholar
Vansant, E.F. and Peeters, G., (1978) Exchange of alkylammonium ions on Na-Laponite Clays and Clay Minerals 26 279–284 10.1346/CCMN.1978.0260404.CrossRefGoogle Scholar
Vansant, E.F. and Uytterhoeven, J.B., (1972) Thermodynamics of exchange of n-alkylammonium ions on Na-montmorillonite Clays and Clay Minerals 20 47–54 10.1346/CCMN.1972.0200106.CrossRefGoogle Scholar
Zhang, Z.Z. Sparks, D.L. and Scrivner, N.C., (1993) Sorption and desorption of quaternary amine cations on clays Environmental Science and Technology 27 1625–1631 10.1021/es00045a020.CrossRefGoogle Scholar