Molecular Weight and Charge Density Asymmetry in Polyelectrolyte Complexation

ORAL

Abstract

We investigate the phase diagram of oppositely charged polymers in a good solvent using a field-theoretic model. Mean-field solutions fail to predict the experimentally observed macroscopic phase separation into a solvent-rich phase and a dense liquid aggregate of polymers - a ``complex coacervate.'' We therefore study the model within a one-loop approximation, which accounts for Gaussian fluctuations in electrostatic and chemical potentials. Our particular focus is the effect of molecular weight, ionic strength, and charge asymmetry on the phase envelope. A set of dimensionless parameters is identified that dictate the size and shape of the two-phase region. Our results should be helpful in guiding experimental studies of coacervation.

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Authors

  • Debra Audus

    • University of California, Santa Barbara

  • Glenn Fredrickson

    • UCSB - MC CAM
    • Materials Research Laboratory, University of California, Santa Barbara
    • University of California, Santa Barbara
    • Materials Research Lab, UCSB
    • Department of Chemical Engineering and the Materials Research Laboratory, University of California, Santa Barbara
    • UCSB, USA
    • UC Santa Barbara
    • UCSB

  • Dominik Duechs

    • Max Planck Institute, Mainz