Electrostatic persistence length of NaPSS polyelectrolytes determined by a zero average contrast SANS technique

Abstract

The electrostatic persistence lengths b c of NaPSS polyions have been measured as a function of ionic strength I in the solutions using a small-angle neuron scattering (SANS) technique combined with a zero average contrast (ZAC) method. This ZAC method provides the optical theta condition distinguishing the intermolecular scattering functions S 2( q), and thereby the scattering functions of a single chain S 1( q) free from the intermolecular interferences were obtained. The resulting b c values which were derived by the analysis of S 1( q) are proportional to I −1 2 . This work confirms and extends an earlier SANS study where the contrast-match was used.