Osmotic coefficients of polystyrenesulphonates in dioxane-water mixtures—I Monovalent counterions

The osmotic pressures of solutions of polystyrenesulphonic acid and its alkali salts in water, and in 25 and 50 wt% mixtures of dioxane in water have been measured for concentrations from about 0-001 to 0–03 M in monomer units. The osmotic coefficient derived from these measurements decreases with decreasing dielectric constant of the solvent and increases slowly with increasing concentration of the polyelectrolyte. By comparing the experimental results with the predictions of the cylindrical cell model and infinite line charge model, satisfactory agreement between theory and experiment has been obtained.