The exponent of concentration in viscosity-concentration power law

=K.ca have been studied for the concentrated solutions of the sulfonated polysulfones with different degree of sulfonation (IEC = 0~0.93 mmol/g) in 3 dimethylformamide/toluene (3/1 volume ratio) mixed solvents without and with added salt (0.07 mol NaNO3) at 30℃.The exponent decreases with increasing degree of sulfonation in salt solution (a = 4.29 ~ 3.52)

and was consistently higher in salt-free solution (a = 4.09~3.03). And the results were discussed with a scaling approach.