Effect of Different Low‐Molar Mass Electrolytes on the Viscometric Behaviour of Sodium Polystyrenesulfonate in Methanol–Water Mixed Solvent Media

Abstract

SummaryPrecise measurements on the viscosities of sodium polystyrenesulfonate (NaPSS) in water as well as in methanol–water mixed solvent media have been reported in presence of NaCl, KCl, NaBr and KBr having concentrations of 0.1 and 0.5 mol.L−1 at 308.15 K with the polyelectrolyte concentrations in the range ∼ 0.001 to ∼ 0.012 eqv L−1. The reduced viscosities of the polyelectrolyte solutions vary linearly with polymer concentration for all the systems investigated which enabled us to determine the intrinsic viscosities of sodium polystyrenesulfonate in methanol–water mixtures using the Huggins equation. The coiling of the polyion chains are found to increase in the order: NaPSS‐NaCl < NaPSS‐NaBr < NaPSS‐KCl < NaPSS‐KBr. The solvodynamic dimensions of the polyion coils are found to be reduced as the relative permittivity of the medium decreases. The present study also indicates that the polyion structures become more compact with increasing salt concentration in the medium.