The effects of dynamic binding on the phase behavior and properties of polymer blends undergoing complex coacervation

In many polymer systems, liquid-liquid phase separation (LLPS) is driven by a combination of driving forces, which could include hydrophobic interactions, electrostatics as in complex coacervation, or dynamic association as in network formation. This is particularly true for biopolymers, which undergo LLPS to create membraneless organelles. However, fundamental studies of the interactions between multiple driving forces for phase separation have received less attention, and with the emerging importance of membraneless organelles in regulating some diseases, understanding how multiple driving forces interact to drive LLPS is important. In this talk we present the results of a computational study focused on inducing LLPS using a combination of coacervation and dynamic binding. As opposed to the previous research on dynamically linked systems, where bonding forces dominate, we treat dynamic binding as a perturbation on top of electrostatic forces. We explore the how the thermodynamic and dynamical properties, such as chain diffusion and network structure, change as we vary the number of binding sites on the chains as well as the affinity between the species. Finally, we demonstrate that by combining polymers belonging to two binding types, we can induce bond-driven orthogonal phase separation where the polymer-rich phase separates into two distinct polymer-rich phases.