Stretching necklaces
T.A. Vilgis, - A. Johner - J.F. Joanny
Laboratoire
Européen Associé, Institut Charles Sadron, 6 rue
Boussingault, F- 67083 Strasbourg, Cedex, France
vilgis@mpip-mainz.mpg.de
Received 6 December 1999
Abstract
Polyelectrolytes in poor solvents show a necklace structure where
collapsed polymer pearls are linked to stretched strings. In the
present paper the elasticity of such chains is studied in detail.
Different deformation regimes are addressed. The first is the
continuous regime, where many pearls are present. A continuous
force extension relationship is calculated. The main contribution
comes from the tension balance and the electrostatic repulsion of
consecutive pearls. The main correction term stems from the finite
size of the pearls, which monitors their surface energy. For a
finite amount of pearls discontinuous stretching is predicted.
Finally counterion effects are discussed qualitatively.
PACS
36.20.-r Macromolecules and polymer molecules
- 61.25.Hq Macromolecular and polymer solutions; polymer melts; swelling
- 61.41.+e Polymers, elastomers, and plastics
Copyright EDP Sciences, Società Italiana di Fisica, Springer-Verlag
