Electrical Conductivity of a Semidilute Polyelectrolyte in Mixed Solvent Media

Abstract

The electrical conductivity of solutions of sodium salt of polystyrenesulfonate in methanol-water mixed solvent media containing 8, 16, 25, and 34 weight per cent of methanol at 308.15, 313.15, 318.15 and 323.15 K was studied earlier. In that report, an attempt was made to interprete the results using the Manning Counterion Condensation Theory. Unfortunately, a major deviation of the theoretical prediction from the experimental results was noticed and the possible reasons for this discrepancy have been discussed. In this communication, the experimental conductivity have been analyzed on the basis of a new model for semi-dilute polyelectrolyte conductivity which takes into electrical conductivity of semidilute solutions of polyelectrolytes without added salt has been recently described by Colby et al. (1997) using the scaling description proposed by Dobrynin et al. (1995) for the configuration of a polyelectrolyte chain in semi-dilute solution. The predictions are found to be compared favorably well with the observed conductivity over the whole range of concentrations investigated.

Key Words: conductivity; counterion; condensation; semi-dilute; Manning theory

DOI: 10.3126/njst.v9i0.3182

Nepal Journal of Science and Technology 9 (2008) 163-170