Modeling Multivalent-Induced Structural Inhomogeneities in Polyelectrolyte Brushes

ORAL

Abstract

The impact of multivalent salt ions on the morphologies of polyelectrolyte brushes is examined using coarse-grained molecular dynamics simulations, enhanced with free-energy sampling methods. Information derived from simulations is utilized to disentangle the interplay of multivalent and solvophobic effects present in collapsed Na(PSS) polyelectrolyte brushes. Simulations and experiments taken together in both the planar and surface forces apparatus geometries provide evidence for a distinction between the mechanisms of multivalency and solvophobicity in the collapsed brush morphologies, and emphasize the critical role of multivalent ion bridging interactions. The strongly heterogeneous collapsed surface structures observed experimentally are hypothesized to result from the interplay of multivalent and solvophobic effects.

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Presenters

  • Nicholas Jackson

    Argonne National Laboratory

Authors

  • Nicholas Jackson

    Argonne National Laboratory

  • Jing Yu

    Materials Science, Nanyang Technological University Singapore

  • Xin Xu

    Chemistry, University of Massachusetts - Lowell

  • Marina Ruths

    Chemistry, University of Massachusetts - Lowell

  • Blair Brettman

    Georgia Tech

  • Matthew Tirrell

    Univ of Chicago, Institute for Molecular Engineering, University of Chicago, Institute of Molecular Engineering, University of Chicago, IME, University of Chicago, Institute for Molecular Engineering, Univ of Chicago, The University of Chicago

  • Juan De Pablo

    Institute for Molecular Engineering, The University of Chicago, Institute for Molecular Engineering, Univ of Chicago, Institute for molecular engineering, The University of Chicago, University of Chicago, Univ of Chicago, Institute for Molecular Engineering, University of Chicago, The Institute for Molecular Engineering, The University of Chicago, Institute of Molecular Engineering, University of Chicago