Clays and Clay Minerals

, Volume 48, Issue 2, pp 246–255 | Cite as

Influence of Organic and Inorganic Salts on the Coagulation of Montmorillonite Dispersions

  • D. PennerEmail author
  • G. Lagaly


The colloidal state (stable, coagulated, or gel-like) and the rheological properties of Na-rich montmorillonite (Wyoming) dispersions are strongly influenced by organic cations. This effect is shown for homologous organic cations: alkyl trimethylammonium ions, paraquat, diquat, alkyl bispyridinium ions, and the triphenylmethane dyes crystal violet, methyl green, and tris (tri-methylammonium phenyl) methane chloride. The critical coagulation concentrations, cK, are small (often < 1 mmol/L) because the cations are enriched in the Stern layer and influence the solvent structure near the surface. The strong adsorption of the counterions at the clay-mineral surface causes cK values to increase with the solid content. Charge reversal (recharging) of the particles was observed with the longer chain alkyl trimethyl-ammonium ions, dodecyl bispyridinium ions, and crystal violet. Other cations reduced the electrophoretic mobility to zero but positive particle charges were not observed.

The plastic viscosity increased sharply at the critical coagulation concentration and showed a minimum slightly below cK, which was caused by the electroviscous effect. Yield values were developed at concentrations above cK. In most cases, yield values reached a plateau where the amount of organic cations was ∼0.5 mmol/g, i.e., about half of the cation-exchange capacity. The cK values decreased with increasing hydrophobicity of homologous compounds, but the yield value showed maxima at intermediate chain lengths. The yield value of several 0.5% dispersions was high, e.g., dodecyl trimethylammonium ions, 71 Pa; paraquat, 100 Pa; diquat, 42 Pa; hexyl bispyridinium ions, 53 Pa (vs. Ca2+, 0.2 Pa; Al3+, 0.7 Pa). The storage modulus as a function of the number of organic cations changed in a similar way as the yield value, and high values were observed (e.g., dodecyl trimethylammonium ions, hexyl bispyridinium ions: 1000 Pa, paraquat: >4000 Pa). Thus, dispersions with high viscosity, yield value, and pronounced viscoelasticity are obtained by coagulating Na-rich montmorillonite dispersions with organic cations.

Key Words

Alkyl Bispyridinium Ions Alkyl Trimethylammonium Ions Critical Coagulation Concentration Colloids Crystal Violet Diquat Flocculation Methyl Green Montmorillonite Paraquat Rheology Viscoelasticity 


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  1. Abend, S. and Lagaly, G. (2000) Sol-gel transitions of bentonite dispersions. Applied Clay Science, 16, 201–227.CrossRefGoogle Scholar
  2. Bohmer, M.R. and Koopal, L.K. (1992) Adsorption of ionic surfactants on variable-charge surfaces. 1. Charge effects and structure of the adsorbed layer. Langmuir, 8, 2649–2659.CrossRefGoogle Scholar
  3. Brüdgam, I. and Hard, H. (1986) Dipyridiniomethan-Diiodid. Acta Crystallographica C, 42, 866–868.CrossRefGoogle Scholar
  4. Chan, D.Y.C., Pashley, R.M., and Quirk, J.P. (1984) Surface potentials derived from co-ion exclusion measurements on homoionic montmorillonite and illite. Clays and Clay Minerals, 32, 131–138.CrossRefGoogle Scholar
  5. Gan, H. and Low, F. (1993) Spectroscopic study of ionic adjustments in the electric double layer of montmorillonite. Journal of Colloid and Interface Science, 161, 1–5.CrossRefGoogle Scholar
  6. Goldberg, S. (1992) Use of surface complexation models in soil chemical systems. Advanced Agronomy, 47, 233–329.CrossRefGoogle Scholar
  7. Gregory, J. (1973) Rates of flocculation of latex particles by cationic polymers. Journal of Colloid and Interface Science, 42, 448–456.CrossRefGoogle Scholar
  8. Güven, N. (1992) Rheological aspects of aqueous smectite suspensions. In Clay-Water Interface and its Rheological Implications, N. Güven and R.M. Pollastro, eds., CMS Workshop Notes Volume 4, The Clay Minerals Society, Boulder, Colorado, 81–126.Google Scholar
  9. Haque, R., Lilley, S., and Coshow, W.R. (1970) Mechanism of adsorption of diquat and paraquat on montmorillonite surface. Journal of Colloid and Interface Science, 33, 185–188.CrossRefGoogle Scholar
  10. Hasenpatt, R., Degen, W., and Kahr, G. (1989) Flow and diffusion in clays. Applied Clay Science, 4, 179–192.CrossRefGoogle Scholar
  11. Hochstein, B. and Geissle, W. (1995) Linear viscoelastic region exhibited by pure fluids and their suspensions. Rheology, 5, 72–79.Google Scholar
  12. Ijdo, W.L. and Pinnavaia, T.J. (1998) Staging of organic and inorganic gallery cations in layered silicate heterostructures. Journal of Solid State Chemistry, 139, 281–289.CrossRefGoogle Scholar
  13. Israelachvili, J. (1994) Intermolecular and Surface Forces. Academic Press, London, 450 pp.Google Scholar
  14. Knight, G.A. and Shaw, B.D. (1938) Long chain alkylpyridines and their derivatives. New examples of liquid crystals. Journal of the American Chemical Society, 121, 682–683.CrossRefGoogle Scholar
  15. Lagaly, G. (1986a) Smectite clays as ionic macromolecules. In Developments in Ionic Polymers, Volume 2, A.D. Wilson and H.J. Prosser, eds, Elsevier Applied Science Publication Ltd., London, 77–140.CrossRefGoogle Scholar
  16. Lagaly, G. (1986b) Colloids. In Ullmann’s Encyclopedia of Industrial Chemistry, Volume A7, VCH Verlagsgesellschaft, Weinheim, 341–367.Google Scholar
  17. Lagaly, G. (1987) Water and solvents on surfaces bristling with alkyl chains. In Interaction of Water in Ionic and NonIonic Hydrates, H. Kleeberg, ed., Springer-Verlag, Berlin, 229–239.CrossRefGoogle Scholar
  18. Lagaly, G. (1993a) Praktische Verwendung und Einsatzmöglichkeiten von Tonen. In Tonminerale und Tone—Struktur, Eigenschaften, Anwendungen und Einsatz in Industrie und Umwelt, K. Jasmund and G. Lagaly, eds., Steinkopff-Verlag, Darmstadt, 358–420.Google Scholar
  19. Lagaly, G. (1993b) From clay minerals to colloidal clay mineral dispersions. In Coagulation and Flocculation. Theory and Applications, B. Dobias, ed., Marcel Dekker Inc., New York, 427–494.Google Scholar
  20. Lagaly, G. (1994) Layer charge determination by alkylammonium ions. In Layer Charge Characteristics of 2: 1 Silicate Clay Minerals, A.R. Mermut, ed., CMS Workshop Notes, Volume 6, The Clay Minerals Society, Boulder, Colorado, 1–46.Google Scholar
  21. Lagaly, G. and Witter, R. (1982) Clustering of liquid molecules on solid surfaces. Berichte der Bunsengesellschaft für Physikalische Chemie, 86, 74–80.CrossRefGoogle Scholar
  22. Lagaly, G., Witter, R., and Sander, H. (1983) Water on hydrophobic surfaces. In Adsorption from Solution, R.H. Ottewill, C.H. Rochester, and A.L. Smith, eds., Academic Press, London, 65–77.CrossRefGoogle Scholar
  23. Lagaly, G., Schulz, O., and Zimehl, R. (1997) Dispersionen und Emulsionen. Eine Einführung in die Kolloidik feinverteilter Stoffe einschließlich der Tonminerale (mit einem historischen Beitrag über Kolloidwissenschaftler von Klaus Beneke). Steinkopff Verlag, Darmstadt, 560 pp.Google Scholar
  24. Lagaly, G., Reese, M., and Abend, S. (1999) Smectites as colloidal stabilizers of emulsions. II. Rheological properties of smectite-laden emulsions. Applied Clay Science, 14, 279–298.CrossRefGoogle Scholar
  25. Lyklema, J. (1994) Adsorption of ionic surfactants on clay minerals and new insights in hydrophobic interactions. Progress in Colloid and Polymer Science, 95, 91–97.CrossRefGoogle Scholar
  26. Margulies, L. and Rozen, H. (1986) Adsorption of methyl green on montmorillonite. Journal of Molecular Structure, 141, 219–226.CrossRefGoogle Scholar
  27. Overbeek, J.T.G. (1980) The rule of Schulze and Hardy. Pure and Applied Chemistry, 52, 1151–1161.CrossRefGoogle Scholar
  28. Permien, T. and Lagaly, G. (1994a) The rheological and colloidal properties of bentonite dispersions in the presence of organic compounds. I. Flow behaviour of sodium montmorillonite in water-alcohol. Clay Minerals, 29, 751–760.Google Scholar
  29. Permien, T. and Lagaly, G. (1994b) The rheological and colloidal properties of bentonite dispersions in the presence of organic compounds. III. The effect of alcohols on the coagulation of sodium montmorillonite. Colloid and Polymer Science, 272, 1306–1312.CrossRefGoogle Scholar
  30. Philen, O.D., Jr., Weed, S.B., and Weber, J.B. (1970) Estimation of surface charge density of mica and vermiculite by competitive adsorption of diquat vs paraquat. Soil Science Society of America Proceedings, 34, 527–531.CrossRefGoogle Scholar
  31. Philen, O.D., Jr, Weed, S.B., and Weber, J.B. (1971) Surface charge characterization of layer silicates by competitive adsorption of two organic divalent cations. Clays and Clay Minerals, 19, 295–302.CrossRefGoogle Scholar
  32. Quirk, J.P. and Marčelja, S. (1997) Application of doublelayer theories to the extensive crystalline swelling of Li+-montmorillonite. Langmuir, 13, 6241–6248.CrossRefGoogle Scholar
  33. Raupach, M., Emerson, W.W., and Slade, P.G. (1979) The arrangement of paraquat bound by vermiculite and montmorillonite. Journal of Colloid and Interface Science, 69, 398–408.CrossRefGoogle Scholar
  34. Rooy, N. de, Bryn, P.L. de, and Overbeek, J.T.G. (1980) Stability of dispersions in polar organic media. I. Electrostatic stabilization. Journal of Colloid and Interface Science, 75, 542–554.CrossRefGoogle Scholar
  35. Rytwo, G., Nir, S., and Margulies, L. (1993) Competitive adsorption of methylene blue and crystal violet to montmorillonite. Clay Minerals, 28, 139–143.CrossRefGoogle Scholar
  36. Rytwo, G., Nir, S., Margulies, L. (1995). Interactions of monovalent organic cations with montmorillonite: Adsorption studies and model calculations. Soil Science Society of America Journal, 59, 554–564.CrossRefGoogle Scholar
  37. Rytwo, G., Nir, S., and Margulies, L. (1996a) A model for adsorption of divalent organic cations to montmorillonite. Journal of Colloid and Interface Science, 181, 551–560.CrossRefGoogle Scholar
  38. Rytwo, G., Nir, S., and Margulies, L. (1996b) Adsorption and interactions of diquat and paraquat with montmorillonite. Soil Science Society of America Journal, 60, 601–610.CrossRefGoogle Scholar
  39. Schmidt, C.U. and Lagaly, G. (1999) Surface modification of bentonites. I. Betaine montmorillonites and their rheological and colloidal properties. Clay Minerals, 34, 447–458.CrossRefGoogle Scholar
  40. Schneider, H.J., Schiestel, T., and Zimmermann, P. (1992) The incremental approach to nonvalent interactions: Coulomb and van-der-Waals effects in organic ion pairs. Journal of the American Chemical Society, 114, 7698–7703.CrossRefGoogle Scholar
  41. Schramm, L.L. and Kwak, J.C.T. (1982) Interactions in clay suspensions: The distribution of ions in suspension and the influence of tactoid formation. Colloids and Surfaces, 3, 43–60.CrossRefGoogle Scholar
  42. Schramm, L.L., Yariv, S., Ghosh, D.K., and Hepler, L.G. (1997) Electrokinetic study of the adsorption of ethyl violet and crystal violet by montmorillonite clay particles. Canadian Journal of Chemistry, 75, 1868–1877.CrossRefGoogle Scholar
  43. Stul, M.S. and van Leemput, L. (1982) Particle-size distribution, cation exchange capacity and charge density of deferrated montmorillonites. Clay Minerals, 17, 209–215.CrossRefGoogle Scholar
  44. Stumm, W., Huang, C.P., and Jenkins, S.R. (1970) Specific chemical interaction affecting the stability of dispersed systems. Croatica Chemica Acta, 42, 223–244.Google Scholar
  45. Tributh, H. and Lagaly, G. (1986) Aufbereitung und Identifizierung von Boden- und Lagerstattentonen. GIT Fachzeitschrift für das Laboratorium, 30, 524–529, 771–776.Google Scholar
  46. Weed, S.B. and Weber, J.B. (1969) The effect of cation exchange capacity on the retention of diquat and paraquat by three-layer type clay minerals. I. Adsorption and release. Soil Science Society of America Proceedings, 33, 379–382.CrossRefGoogle Scholar
  47. Wienberg, R. (1990) Zum Einfluß organischer Schadstoffe auf Deponietone. Abfallwirtschaftsjournal, 6, 393–403.Google Scholar
  48. Xu, S. and Boyd, S.A. (1995) Cationic surfactant adsorption by swelling and nonswelling layer silicates. Langmuir, 11, 2508–2514.CrossRefGoogle Scholar
  49. Yariv, S., Müller-Vonmoos, M., Kahr, G., and Rub, A. (1989) Thermal analytical study of the adsorption of crystal violet by laponite. Journal of Thermal Analysis, 35, 1941–1952.CrossRefGoogle Scholar
  50. Yariv, S., Nasser, A., and Baron, P. (1990) Metachromasy in clay minerals. Spectroscopic study of the adsorption of crystal violet by laponite. Journal of the the Chemical Society Faraday Transactions, 86, 1593–1598.CrossRefGoogle Scholar

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© The Clay Minerals Society 2000

Authors and Affiliations

  1. 1.Institute of Inorganic ChemistryUniversity of KielKielGermany

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