Concentration Dependence of Radius of Gyration of Sodium Poly(styrenesulfonate) over a Wide Range of Concentration Studied by Small-Angle Neutron Scattering

Abstract

Concentration dependence of radius of gyration ( R g ) of sodium poly(styrenesulfonate)s (NaPSS) in aqueous solutions without added salt was studied by small-angle neutron scattering measurements over a wide range of concentration. The R g values are always higher than those of corresponding nonionic polymer, polystyrene, and the concentration ( C ) dependence of R g of NaPSS in the semidilute region ( C < 0.3 × 10 3 kg/m 3 ) can be well expressed by the scaling relation ( R g ∝ C -1/4 ), while R g values in the concentrated region are almost constant at the value almost equal to that at ϑ condition. The crossover concentration from the semidilute to concentrated regions was also consistent with our previous studies of viscoelastic properties of polyelectrolyte solutions without added salts.