2016 AIChE Annual Meeting

(397b) Dynamics in Weakly-Ordered Oppositely-Charged Polyelectrolyte Complex Solutions

Authors

Anand Rahalkar - Presenter, National Institute of Standards and Technology
Vivek M. Prabhu, National Institute of Standards and Technology
Guangmin Wei, National Institute of Standards and Technology
Samanvaya Srivastava, University of Chicago
Matthew V. Tirrell, University of Chicago
Recent experiments by Krogstad et al [1] determined the phase diagram of coacervate hydrogels formed by oppositely-charged triblock polyelectrolytes. Disordered and ordered phases were observed on the salt concentration-polymer concentration plane as determined by small-angle scattering methods and cryo-transmission electron microscopy. The ordered phases were in agreement with equilibrium structures calculated with an embedded fluctuation model by Audus et al [2]. Of current interest is in the dynamics of these highly-charged polyelectrolyte hydrogels. A close examination of the dilute disordered region by dynamic light scattering show strong clustering behavior. These large-scale clusters in the disordered region are a hierarchical assembly of micelles building blocks. The equilibrium between clusters and micelles was examined for well-defined 1:1 stoichiometric by charge mixtures of anionic and cationic functionalized poly(allyl glycidyl ether) end blocks with poly(ethylene glycol) middle block. Our new small-angle neutron scattering and dynamic light scattering results will be discussed to understand the solution structure on the temperature-concentration phase diagram plane.

[1] DV Krogstad et al. Macromolecules, 46, 1512 (2013). DV Krogstad et al. J. Phys. Chem. B, 118, 13011 (2014).

[2] DJ Audus et al. Soft Matter, 11, 1214 (2015).