Factors Governing Polyelectrolyte Complexation in Non-Ideal Environments

The phase behavior and viscoelastic properties of polyelectrolyte complexes (PECs) comprising oppositely charged polyelectrolytes (PEs) are influenced by solution conditions (ionic strength, pH) and properties of the charged PEs (concentration, molecular weight, chemistry). These studies are, however, performed in model systems, where properties of the solution and polymers are well-controlled. In real systems where PEs are employed, they are often exposed to non-ideal conditions, and little to no control can be exercised over the solution conditions and PE properties. The factors influencing PE complexation under these conditions remain to be probed. Previously, we showed that introduction of divalent ions (often encountered in biological and wastewater systems) in charge-matched PECs reverses the phase composition and induces hindered chain relaxation. In this talk, non-idealities in PE composition and architecture will be addressed to mimic and represent realistic conditions under which PE complexation occurs. These non-idealities will be shown to influence the extent of complexation, salt resistance, phase composition, and viscoelastic behavior in PECs. Further, a design guide for inducing complexation and altering the processability of these PE complexes will be discussed.