Excitonically Coupled Simple Coacervates via Liquid/Liquid Phase Separation

• Published in: The journal of physical chemistry letters 2022-11, Vol.13 (44), p.10275-10281
• Main Authors: Johnston, Anna R., Pitch, Gregory M., Minckler, Eris D., Mora, Ivette G., Balasco Serrão, Vitor H., Dailing, Eric A., Ayzner, Alexander L.
• Format: Article
• Language: English
• Subjects: Anions; Diffusion; Excitons; Hydrogen-Ion Concentration; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Letter; Liquids; Phase separation; Physical Insights into Materials and Molecular Properties; Polyelectrolytes; Quantum mechanics; Water
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.2c02466

Viscoelastic liquid coacervate phases that are highly enriched in nonconjugated polyelectrolytes are currently the subject of highly active research from biological and soft-materials perspectives. However, formation of a liquid, electronically active coacervate has proved highly elusive, since extended π-electron interactions strongly favor the solid state. Herein we show that a conjugated polyelectrolyte can be rationally designed to undergo aqueous liquid/liquid phase separation to form a liquid coacervate phase. This result is significant both because it adds to the fundamental understanding of liquid/liquid phase separation but also because it opens intriguing applications in light harvesting and beyond. We find that the semiconducting coacervate is intrinsically excitonically coupled, allowing for long-range exciton diffusion in a strongly correlated, fluctuating environment. The emergent excitonic states are comprised of both excimers and H-aggregates.