Ion condensation onto self-assembled nanofibers

Elad Deiss-Yehiely, Julia H. Ortony, Baofu Qiao, Samuel I. Stupp, Monica Olvera de la Cruz

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Self-assembled peptide amphiphile (PA) nanofibers are a class of supramolecular materials with promising applications in nanotechnology. Alignment of nanofibers, which is essential for biomaterials applications, is achieved at low salt concentrations in the PA nanofiber suspensions. Regardless of its importance, the effect of ion concentration on the properties of these nanostructures remains unexplored. Using atomistic molecular dynamics simulations, canonical PA nanostructures are investigated to elucidate the relationship between counterion condensation and morphological changes. Simulations reveal that nanofibers with the highest cross-section density have expanded radii. This expansion decreases the accessible volume for sodium counterions and diminishes the counterion translational entropy, while also reducing the total electrostatic potential. Interestingly, we show that the competition between these effects leads to a fraction of condensed counterions independent of the fiber radius.

Original languageEnglish
Pages (from-to)901-906
Number of pages6
JournalJournal of Polymer Science, Part B: Polymer Physics
Volume55
Issue number12
DOIs
Publication statusPublished - Jun 15 2017

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Keywords

  • counterion condensation
  • molecular dynamics simulation
  • nanofiber
  • peptide amphiphile
  • self-assembly

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Polymers and Plastics
  • Materials Chemistry

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