Excitonically\nCoupled Simple Coacervates via Liquid/Liquid\nPhase Separation

Abstract

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