Molecular Origin of the Glass Transition in Polyelectrolyte Assemblies

Research output: Contribution to journalArticleScientificpeer-review

Researchers

Research units

  • Texas A and M University
  • Institute of Catalysis and Surface Chemistry of the Polish Academy of Sciences

Abstract

Water plays a central role in the assembly and the dynamics of charged systems such as proteins, enzymes, DNA, and surfactants. Yet it remains a challenge to resolve how water affects relaxation at a molecular level, particularly for assemblies of oppositely charged macromolecules. Here, the molecular origin of water's influence on the glass transition is quantified for several charged macromolecular systems. It is revealed that the glass transition temperature (Tg) is controlled by the number of water molecules surrounding an oppositely charged polyelectrolyte-polyelectrolyte intrinsic ion pair as 1/Tg ∼ ln(nH2Onintrinsic ion pair). This relationship is found to be "general", as it holds for two completely different types of charged systems (pH- and salt-sensitive) and for both polyelectrolyte complexes and polyelectrolyte multilayers, which are made by different paths. This suggests that water facilitates the relaxation of charged assemblies by reducing attractions between oppositely charged intrinsic ion pairs. This finding impacts current interpretations of relaxation dynamics in charged assemblies and points to water's important contribution at the molecular level.

Details

Original languageEnglish
Pages (from-to)638-644
Number of pages7
JournalACS Central Science
Volume4
Issue number5
Publication statusPublished - 23 May 2018
MoE publication typeA1 Journal article-refereed

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