Tracer diffusion, electrical conductivity, and viscosity of aqueous solutions of polystyrenesulfonates

Abstract

AbstractThe variation of counterion mobilities in aqueous solutions of linear sodium polystyrenesulfonic acid over wide range of concentrations (10−2–0.7N) was studied. The viscosities of these solutions were measured in order to calculate the reduced viscosities at different concentrations. From the data obtained it was possible to conclude that in the range of concentrations 0.08–0.45N, an increase in D was observed. The enhancement of mobilities was attributed to an increase in the degree of apparent dissociation due to purely electrostatic interactions among neighboring chains. As concentration increased and chains approached each other, the above interactions should be accompained by short‐range interactions which would produce entanglements among neighbouring chains. This may be responsible for the appearance of a maximum in mobilities as the concentration increased. Evidence was found for a decrease of DNa in solution when N > 0.45. The appearance of entanglements must produce an increase in the reduced viscosity which was observed. Tracer diffusion coefficients and reduced viscosities of the counterions Cs+, Ag+, and Ca++ in the corresponding salts of polystyrenesulfonic acid all at the same normalities were also measured. It was observed that the counterions Cs+ had a slightly larger degree of association than Na+. The behavior of Ca++ could be explained by the very strong association due to its double charge and for silver as partially due to the presence of complexes. For both counterions the reduced viscosity was much smaller than for the sodium salt.