ON THE CHARGE-DISTRIBUTION IN AQUEOUS POLY(STYRENESULFONIC ACID) SOLUTIONS - A SMALL-ANGLE NEUTRON-SCATTERING STUDY

The partial structure functions and the charge structure function are obtained for aqueous solutions of poly(styrenesulfonate) without excess low molecular weight salt. In the momentum-transfer range q > 0.1 angstrom-1, the structure functions are interpreted in terms of the correlation functions derived from the exact solution of the Poisson-Boltzmann equation in the cell model. The local polymer structure can well be approximated by a rod-like configuration with a rather high linear charge density. The derived charge density is, however, in agreement with the relatively low value of the osmotic coefficient for vinylic polyelectrolytes.