Molecular mass and ionic strength dependence of electrochemical properties of flexible polyelectrolytes

Conductometry and potentiometry have been employed to examine the influence of macromol. parameters and chem. structure on the electrochem. behavior of flexible polyelectrolytes with finite chain length in the concn. range 10-6 < cp < 10-2 monomol.l-1. For polyelectrolytes with charge distances below the Bjerrum length at low ionic strength the equiv. cond. increases strongly with decreasing polymer concn. Correlating this behavior with concn. regimes according to de Gennes and Odijk the strong and nearly linear increase is situated below the overlap concn. In highly dild. polyelectrolyte solns. without and with addn. of low mol. electrolyte the equiv. cond. reaches a limit whose abs. high and position was found to have strong correlations with the mol. mass, the ionic strength, and the ratio of polyelectrolyte to salt concn. The electrolytic cond. results correspond with counterion activities in the concn. range cp > 10-4 monomol.l-1. The discussion of the findings in terms of existing theories point to defined charges of the interionic interactions. [on SciFinder (R)]