Polyelectrolyte

Chemical structures of two synthetic polyelectrolytes, as examples. To the left is poly(sodium styrene sulfonate) (PSS), and to the right is polyacrylic acid (PAA). Both are negatively charged polyelectrolytes when dissociated. PSS is a 'strong' polyelectrolyte (fully charged in solution), whereas PAA is 'weak' (partially charged).

Polyelectrolytes are polymers whose repeating units bear an electrolyte group. Polycations and polyanions are polyelectrolytes. These groups dissociate in aqueous solutions (water), making the polymers charged. Polyelectrolyte properties are thus similar to both electrolytes (salts) and polymers (high molecular weight compounds) and are sometimes called polysalts. Like salts, their solutions are electrically conductive. Like polymers, their solutions are often viscous. Charged molecular chains, commonly present in soft matter systems, play a fundamental role in determining structure, stability and the interactions of various molecular assemblies. Theoretical approaches[1][2] to describe their statistical properties differ profoundly from those of their electrically neutral counterparts, while technological and industrial fields exploit their unique properties. Many biological molecules are polyelectrolytes. For instance, polypeptides, glycosaminoglycans, and DNA are polyelectrolytes. Both natural and synthetic polyelectrolytes are used in a variety of industries.

IUPAC definition

polyelectrolyte: Polymer composed of macromolecules in which a substantial portion of the constitutional units contains ionic or ionizable groups, or both. (See Gold Book entry for note.) [3]

  1. ^ de Gennes, Pierre-Gilles (1979). Scaling Concepts in Polymer Physics. Cornell University Press. ISBN 0-8014-1203-X.
  2. ^ Chremos, A.; Horkay, F. (2020-07-27). "Disappearance of the polyelectrolyte peak in salt-free solutions". Phys. Rev. E. 102 (1). American Physical Society (APS): 012611. Bibcode:2020PhRvE.102a2611C. doi:10.1103/PhysRevE.102.012611. PMC 8243406. PMID 32794995.
  3. ^ "polyelectrolyte". Gold Book. IUPAC. 2014. doi:10.1351/goldbook.P04728. Retrieved 1 April 2024.