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Potentiometric, Electrical Conductance and Self-Diffusion Measurements in Clay-Water Systems

Published online by Cambridge University Press:  01 January 2024

R. G. Gast  and
Peggy J. East
R. G. Gast
Affiliation:
Agricultural Research Laboratory of The University of Tennessee, Oak Ridge, Tennessee, USA
Peggy J. East
Affiliation:
Agricultural Research Laboratory of The University of Tennessee, Oak Ridge, Tennessee, USA
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Abstract

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Potentiometric measurements using commercially available cationic glass electrodes, electrical conductance and self-diffusion measurements of cations and water were made in electrolyte-free 3–5 per cent Li, Na, K, Cs, Ca and Sr bentonite-water systems and bi-ionic systems with varying ratios of K and Ca. Activation energies for conductance in the homoionic clays were calculated using the Arrhenius equation.

The agreement between cation mobilities measured by diffusion and conductance indicates that the underlying mechanism is essentially the same for the two processes. But the activation energies for ion movement determined for conductance measurements do not explain the observed reduction in mobility. Only two clays, Li and Cs, gave values significantly higher than for the measured solution conductance and only the Cs clay gave a value higher than those calculated for ion conductance at infinite dilution.

Increasing Ca saturation in K-Ca clays from 1 to 99 per cent increased the self-diffusion coefficient or mobility of K by a factor of about 1.7 and Ca by a factor of about 30 reflecting the effect of the predominate accumulation of the divalent cation in regions of highest negative potential. The reduction in activity of monovalent cations calculated from the potentiometric measurements, although of the same order of magnitude, was consistently less than the corresponding reduction in mobility in both the homoionic and bi-ionic clays. This difference became greater with increasing mobility of K in the bi-ionic clays.

Type
General
Information
Clays and Clay Minerals (National Conference on Clays and Clay Minerals) , Volume 12 , February 1963 , pp. 297 - 310
Copyright
Copyright © The Clay Minerals Society 1963

Footnotes

This manuscript is published with the permission of the Director of the University of Tennessee Agricultural Experiment Station, Knoxville.

Operated by the Tennessee Agricultural Experiment Station for the U.S. Atomic Energy Commission under Contract No. AT-40-1-GEN-242.

References

Bloksma, A. H. (1957) The diffusion of sodium and iodide ions and of urea in clay pastes: J. Colloid Sci., v. 12, pp. 40–52.CrossRefGoogle Scholar
Bower, C. A. (1959) Determination of sodium in saline solutions with a glass electrode: Soil Sci. Soc. Proe., v. 123, pp. 29.CrossRefGoogle Scholar
Dutt, Gordon R., and Low, Philip F. (1962) Relationship between the activation energies for deuterium oxide diffusion and exchangeable ion conductance in clay systems: Soil Sci., v. 93, pp. 195–203.CrossRefGoogle Scholar
Gast, R. G. (1962) An interpretation of self-diffusion measurements of cations in clay-water systems: J. Colloid Sci., v. 17, pp. 492–500.CrossRefGoogle Scholar
Gast, R. G. (1963) Relative effects of tortuosity, electrostatic attraction and increased viscosity of water on self-diffusion rates of cations in bentonite-water systems: Proceedings of the 1963 International Clay Conf., Pergamon Press, New York, pp. 251–259.Google Scholar
Helfferich, F. (1962) Ion Exchange: McGraw-Hill, New York.Google Scholar
Glasstone, Samuel, (1942) An Introduction to Electrochemistry: van Nostrand, New York .Google Scholar
Glasstone, Samuel (1946) Textbook of Physical Chemistry, van Nostrand, 2nd ed., New York.Google Scholar
Glasstone, S., Laidler, K. J., and Eyring, H. (1941) The Theory of Rate Processes: McGraw-Hill, New York.Google Scholar
Lai, T. M., and Mortland, M. M. (1961) Diffusion of ions in bentonite and vermiculite: Soil Sci. Soc. Am. Proc., v. 25, pp. 353–357.CrossRefGoogle Scholar
Lai, T. M., and Mortland, M. M. (1962) Self-diffusion of exchangeable cations in bentonite: Clays and Clay Minerals, 9th Conf., Pergamon Press, New York, pp. 229–247.CrossRefGoogle Scholar
Low, Philip F. (1961) Physical chemistry of clay-water interaction: Advances in Agronomy, v. 13, pp. 269–327.CrossRefGoogle Scholar
Low, Philip F. (1962) Influence of adsorbed water on exchangeable ion movement: Clays and Clay Minerals, 9th Conf., Pergamon Press, New York, pp. 219–228.CrossRefGoogle Scholar
Marshall, C. E, (1948) The electrochemical properties of mineral membranes. VIII. The theory of selective membrane behavior: J. Phys. and Colloid Chem., v. 52, pp. 1284–1295.CrossRefGoogle Scholar
Marshall, C. E. (1951) The activities of cations held by soil colloids and the chemical environment of plant roots: Mineral Nutrition of Plants, chap. 3, E. Truog, ed., University of Wisconsin Press, Madison, Wisconsin.Google Scholar
Marshall, C. E. (1956) Thermodynamic, quasithermodynamic, and nonthermodynamic methods as applied to the electrochemistry of clays: Clays and Clay Minerals, Nat'l. Acad. Sci.— Naťl. Research Council, pub. 456, pp. 288–300.Google Scholar
Marshall, C. E., and Krinball, C. A. (1942) The clays as colloidal electrolytes: J. Phys. Chem., v. 46, pp. 1077–1090.CrossRefGoogle Scholar
Oster, James D., and Low, Philip F. (1963) Activation energy for. ion movement in thin water films on montmorillonite: Soil Sci. Soc. Am. Proc., v. 27, pp. 369–373.CrossRefGoogle Scholar
Overbeek, J. Th. G. (1952) in Colloid Science, Part I, H. R. Kruyt ed. Elsevier, New York.Google Scholar
Overbeek, J. Th. G. (1953) Donnan—e.m.f, and suspension effect: J. Colloid Sci., v. 8, pp. 593–605.CrossRefGoogle Scholar
Porter, L. K., Kemper, W. D., Jackson, R. D., and Stewart, B. A. (1960) Chloride diffusion in soils as influenced by moisture content: Soil Sci. Soc. Am. Proc., v. 24, pp. 460–463.CrossRefGoogle Scholar
Robinson, R. A., and Stokes, R. H. (1955) Electrolyte Solutions: Academic Press, New York.Google Scholar
Rosenqvist, I. Th. (1963) Contributions to discussions to appear in 2nd volume of Proceedings of 1963 International Clay Conference, Stockholm, Sweden.Google Scholar
Sollner, K. (1950) Recent advances in the electrochemistry of membranes of high ionic selectivity: J. Electrochem. Soc., v. 97, рр.139S-151S.CrossRefGoogle Scholar
Spiegler, K. S. (1953) On the electrochemistry of ion-exchange resins— A review of recent work: J. Electrochem, Soc., v. 100, pp, 303C-316C.CrossRefGoogle Scholar
Spiegler, K. S., and Coryell, C. D. (1953) Electromigration in a cation-exchange resin. III. Correlation of self-diffusion coefficients of ions in a cation-exchange membrane to its electrical conductance: J. Phys. Chem., v. 57, pp. 687–690.CrossRefGoogle Scholar
Wang, Jai Hsin (1952) Tracer-diffusion in liquids III. The self-diffusion of chloride ion in aqueous sodium chloride solutions: J. Am. Chem. Soc., v. 74, pp. 1612–1615.CrossRefGoogle Scholar