Chain Configurations of Polymers and Polyelectrolytes

Abstract

On the basis of a rigorous statistical mechanical approach it is shown that the treatments of the configuration of a polyelectrolyte molecule given by Katchalsky and Lifson and by Krieger are equivalent to retaining only the first‐order term of the high temperature expansion of the free energy. Katchalsky's and Lifson's more accurate calculation is exact in the limit of a ``continuous'' chain but the neglected correction terms are shown to be significant. Krieger's approximate expression for the first‐order term is only valid for highly stretched chains and it predicts incorrect results when the interaction potential is appreciable near the origin.