Proton dissociation of sulfonated polysulfones: influence of molecular structure and conformation

Research output: Contribution to journalArticle

Abstract

The dissociation behavior of proton conducting sulfonated polysulfones has been investigated by combining electrophoretic NMR, pulsed magnetic field gradient NMR and conductivity meas- urements on monomeric and polymeric samples with concentrations of ionic groups in the range where dissociation is not complete (IEC = 4.55 – 7.04 meq g-1). In this regime, counterion con- densation is shown to critically depend on details of the molecular structure, and all atom MD simulations reveal the formation of well-defined ionic aggregates (e.g. triple ions). The corre- sponding global minima of the free energy are suggested to be the result of a delicate balance of the energetics involved in conformational changes, formation of ionic aggregates and solvation. This goes beyond Manning’s counterion condensation theory and has important implications for the development of membranes with high ionic conductivity as needed for many electrochemical applications such as fuel cells and batteries.

Details

Authors
  • Andreas Wohlfarth
  • Jens Smiatek
  • Klaus-Dieter Kreuer
  • Shogo Takamuku
  • Patric Jannasch
  • Joachim Maier
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Chemical Sciences
Original languageEnglish
Pages (from-to)1134-1143
JournalMacromolecules
Volume48
Issue number4
Publication statusPublished - 2015
Publication categoryResearch
Peer-reviewedYes

Bibliographic note

Publication Date (Web): February 5, 2015