Advertisement

Clays and Clay Minerals

, Volume 8, Issue 1, pp 122–149 | Cite as

Distribution of Water and Electrolyte Between Homoionic Clays and Saturating NaCl Solutions

  • Fabian Bernstein
Article

Abstract

Ion and water uptake from solution by the sodium and hydrogen forms of montmoril-lonite and illite were measured. The clays first were converted to homoionic form by treatment with synthetic ion exchange resins. The hydrogen clays were used to determine the acid strength of the exchange groups by titration with sodium hydroxide solutions. The sodium clays were used to obtain the ion and water distribution. After attainment of equilibrium with sodium chloride solutions, the sodium clays were centri-fuged to constant weight and the equilibrating solutions analyzed for NaCl. Ion and water uptake and fixed charge concentration in the clays were then measured.

The clay minerals were found to behave as weak acids and the exchange sites are not appreciably dissociated until the pH of the external solution becomes moderately high. In the sodium form, the exchange sites are fully dissociated and the clays, particularly montmorillonite, become efficient Donnan membranes. The partially neutralized clays exhibit intermediate membrane behavior.

At low external phase salinities, the leakage of anions into the clay solution phase is abnormally large, but the membrane activity remains high because of the low activity coefficients of the diffusible ions in the clay phase. At high external solution salinities, the deswelling of the clays and the decrease in the anion to cation mobility ratio partially compensate for the increased anion leakage.

The abnormally low activities of the diffusible ions are directly related to the effect of the internal phase double layer. The concept of ion retardation in the double layer is used to explain the fact that ion transference numbers computed from internal phase ion concentrations are lower than experimental transference numbers.

The relationship of the electrochemical properties of clays to oil-well log interpretation is briefly discussed.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Bernstein, F. and Scala, C. (1959) Some aspects of the streaming potential and the electrochemical SP in shales: Amer. Inst. Mech. Engrs. Pet. Trans., v. 216., pp 465–468.Google Scholar
  2. Davies, J. T. (1958) Monolayers of long-chain ions: in Surface Phenomena in Chemistry and Biology: Pergamon Press, New York, pp. 55–57.Google Scholar
  3. Donnan, F. G. (1924) The theory of membrane equilibria: Chem. Rev., v. 1, pp. 73–90.CrossRefGoogle Scholar
  4. Gregor, H. P. and Gottlieb, M. H. (1953) Studies on ion exchange resins. VIII. Activity coefficients of diffusible ions in various cation-exchange resins: J. Amer. Chem. Soc., v. 75, pp. 3539–3543.CrossRefGoogle Scholar
  5. Gregor, H. P., Luttinger, L. B. and Loebl, E. M. (1955) Metal-polyelectrolyte complexes. I. The Polyacrylic acid-copper complex: J. Phys. Chem., v. 59, pp. 34–39.CrossRefGoogle Scholar
  6. Harned, H. S. and Owen, B. B. (1958) The Physical Chemistry of Electrolytic Solutions: Reinhold Pub. Co., New York.Google Scholar
  7. Kitchener, J. A. (1959) Physical chemistry of ion-exchange resins: in Modern Aspects of Electrochemistry, No. 2, Academic Press, Inc., New York.Google Scholar
  8. Lewis, D. R. (1950) Base-exchange data: in Analytical Data on Reference Clay Materials, Preliminary Rept. no. 7, Reference Clay Minerals, A.P.I. Project 49, Columbia University, New York, pp. 91–124.Google Scholar
  9. Mackay, D. and Meares, P. (1959) The electrical conductivity and electro-osmotic permeability of a cation-exchange resin: Trans. Faraday Soc, v. 55, pp. 1221–1238.CrossRefGoogle Scholar
  10. Thompson, H. S. (1850) On the absorbent power of soils: J. Roy. Agric. Soc, v. 11, pp. 68–74.Google Scholar
  11. van Olphen, H. and Waxman, M. H. (1958) Surface conductance of sodium bentonite in water: in Clays and Clay Minerals, Natl. Acad. Sci.–Natl. Res. Council, pub. 566, pp. 61–80.Google Scholar
  12. Way, J. T. (1850) On the power of soils to absorb manure: J. Roy. Agric. Soc, v. 11, pp. 313–379.Google Scholar

Copyright information

© The Clay Minerals Society 1959

Authors and Affiliations

  • Fabian Bernstein
    • 1
  1. 1.Schlumberger Well Surveying CorporationRidgefildUSA

Personalised recommendations