Osmotic coefficients of polyelectrolyte solutions, measurements and correlation

Osmotic coefficient data for aqueous sodium polyanetholesulfonic acid, sodium polyacrylate and polydiallyl dimethylammonium chloride solutions were determined at 298 K by employing the isopiestic method. The measured osmotic coefficients increase with increasing concentration in the experimental concentration range (0.1–1.5 m). A molecular thermodynamic model developed previously for polyelectrolyte solutions has been used to fit the experimental data. The concentration dependence of the osmotic coefficients can be described satisfactorily.