Phase Behavior and Salt Partitioning in Polyelectrolyte Complexes

ORAL

Abstract

Polyelectrolyte complexes, resulting from associative phase separation of oppositely charged polyelectrolytes, are omnipresent both in nature and technological world. However, the true phase behavior of complexes remains poorly understood. Here we demonstrate complementary experiments and a well-defined simulation model to unveil the complete description of the phase behavior of polyelectrolyte complexes, improving understanding of underlying physics of polyelectrolyte complexation. Experiments with model polypeptides lead to phase diagrams with compositions of the complex and the supernatant, which were in agreements with simulations predictions. Surprisingly, contrary to the widely accepted theory for complexation, we find preferential partitioning of salt ions into the supernatant phase. Upon increasing the salt concentrations, the salt partitioning underwent a unique trend exhibiting a distinct minimum. These trends were revealed by simulations to be strongly influenced by the excluded volume interactions, which were overlooked in the earlier theories.

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Presenters

  • Lu Li

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

Authors

  • Lu Li

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

  • Samanvaya Srivastava

    Univ of California, Los Angeles, Institute for Molecular Engineering, University of Chicago, Institute of Molecular Engineering, University of Chicago, Chemical and Biomolecular Engineering, University of California Los Angeles, Institute for Molecular Engineering, Univ of Chicago, University of California, Los Angeles

  • marat andreev

    Institute for Molecular Engineering, Univ of Chicago

  • 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