Measurements of the Persistence Length of Flexible Polyelectrolytes

We review the experimental results concerning the dependence of the persistence length Lp of flexible polyelectrolytes on the ionic strength I, discussing, in particular, the case of sodium polystyrene sulfonate. In spite of the fact that some disagreement exists among results obtained by different authors and different techniques, the emerging trend is that the electrostatic part of Lp decreases, at large I, proportionally to the Debye-Hückel length, and saturates, at low I, at a value which depends on the contour length L and is much lower than L. The observed overall behavior of Lp versus I seems to disagree with the classical theory proposed by Odijk and by Skolnick and Fixman, and is in qualitative agreement with recent theoretical results. © 1995, Taylor & Francis Group, LLC. All rights reserved.