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.

–

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