The self‐diffusion of ions in a polyelectrolyte solution is investigated both with respect to the average time an ion is associated with a particular polyelectrolyte molecule and with respect to the effect of the electrostatic field of the macro‐ions on the macroscopic self‐diffusion constant. The results on the macroscopic self‐diffusion constant are shown to be generally compatible with experiments on self‐diffusion of counterions in polyelectrolyte solutions. On the other hand, the study of the time of association of a counterion with a particular macro‐ion yields results which cannot be reconciled with the common interpretation of transference experiments on the same solutions.
REFERENCES
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5.
This can be estimated as follows: the kinetic constant of recombination of an ion pair such as, e.g., Na‐acetate, is obtained from Eq. (26) of Onsager’s paper. Expressed in moles per liter it is The smallest value of the equilibrium dissociation constant that we could find in the literature for a Na‐carboxylate ion‐pair is that of Na‐polymethacrylate, and is of the order of [Table I in
R. A.
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7.
A description of this method is also contained in M. Leontowitch, Statistical Mechanics (State Publishing House of Technical‐Theoretical Literature, Moscow, 1944).
Essentially the same results are obtained by a somewhat different method by
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See the recent monograph on Polyelectrolyte Solutions, by S. A. Rice and M. Nagasawa (Academic Press Inc., New York, 1961).
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© 1962 American Institute of Physics.
1962
American Institute of Physics
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