Polyelectrolytes with ionic domains screened by bulky hydrophobic segments form processable, hydrophobic complexes called “compleximers”. Ionic liquids, which are chemically similar, further plasticize compleximers, yet the mechanisms behind their plasticization effects and distribution within the complexes remain unclear. This study examines the relaxation dynamics of plasticized compleximers across multiple length scales using rheology, fluorescence recovery after photobleaching (FRAP), and broadband dielectric spectroscopy (BDS). The incorporation of ionic liquids into compleximers reduces their glass transition temperature (T_g), accelerates diffusive processes, increases segmental motion, and leads to a small decrease in activation energy associated with these relaxation processes. However, the activation energies vary substantially between techniques, probing different physical processes: approximately 200 kJ/mol in rheology, 50 kJ/mol in FRAP, and 90 kJ/mol in BDS. These variations suggest that collective dynamics strongly influence the compleximer rheology, making the mobilization (and activation) of polymer chains distinct from the local movement of ionic segments.

Self-healing polymers can significantly extend the service life of materials and structures by autonomously repairing damage. Intrinsic healing holds great promise as a design strategy to mitigate the risks of damage by delaying or preventing catastrophic failure. However, experimentally resolving the microscopic mechanisms of intrinsic repair has proven highly challenging. This work demonstrates how optical micromechanical mapping enables the quantitative imaging of these molecular-scale dynamics with high spatiotemporal resolution. This approach allows disentangling delocalized viscoplastic relaxation and localized cohesion-restoring rebonding processes that occur simultaneously upon damage to a self-healing polymer. Moreover, frequency- and temperature-dependent imaging provides a way to pinpoint the repair modes in the relaxation spectrum of the quiescent material. These results give rise to a complete picture of autonomous repair that will guide the rational design of improved self-healing materials.