Charged Polymer Systems

 

CoacHiRes

Charged polymers are used in a wide array of applications, ranging from viscosity modification and encapsulation in food products to advanced stimuli-responsive materials. Charged polymers are also ubiquitous in biological materials – most biomacromolecules are charged, which is a crucial aspect of their function. Understanding the physical properties of these systems is thus profoundly important to developing new materials that harness the features of complex biological systems (hierarchical structure, defined monomer sequences, etc.) for the wide array of applications that already feature charged polymers (and more!).

We are interested in a variety of charged polymer materials, in particular a class of polyelectrolyte solutions known as complex coacervates. We are using a combination of simulation and theory to understand the role of charge correlations, molecular shape, polymer monomer sequence, high charge densities, and chain architecture dictate macroscopic electrostatically-driven phase separation. Our work aspires to reveal new ways to manipulate and tune materials using charges. We are pioneering new ways to use polymers and charges to develop materials capable of emulating biology and relevant to applications ranging from advanced stimuli-responsive systems to materials for energy applications.

CoacervateGraphs

Systems comprised of oppositely-charged polymers in the presence of high salt concentrations form ‘complex coacervates’. These systems resemble a gel with transient, electrostatically-driven crosslinks. This is an emerging motif used in self-assembled materials as well as a physical environment resembling biological systems. We have used a combination of simulation and theory (left) to demonstrate how coacervate phase behavior (right) is affected by molecular structure.

 CoacervateFull
We simulate coacervates using a variety of approaches, to capture phase behavior and other material properties. Here, we use a full MD simulation that is consistent with more coarse-grained simulation and theoretical approaches developed in our group.