Electrical conductivity of sodium polystyrenesulfonate in acetonitrile-water-mixed solvent media: experiment and data analysis using the Manning counterion condensation model and the scaling theory approach

摘要

Precise measurements on the electrical conductivity of sodium polystyrenesulfonate in acetonitrile-water-mixed solvent media containing 20 and 40 vol.% of acetonitrile at 308.15, 313.15, and 318.15 K are reported. The mobility of the polyelectrolyte solute was found to be influenced by the polyelectrolyte concentration, the relative permittivity of the medium, and the temperature. The Manning counterion condensation theory for salt-free polyelectrolyte solution failed to describe the experimental results. The data have, therefore, been analyzed on the basis of a new model for semidilute polyelectrolyte conductivity which takes into account the scaling arguments to obtain the fractions of uncondensed counterions which were found to depend on the polyelectrolyte concentration. The effects of the temperature and the relative permittivity of the medium on the equivalent conductivity as well as on the fraction of uncondensed counterions have also been discussed.