Visualizing Energy Transfer Between Redox-Active Colloids

TL;DR

This paper demonstrates real-time visualization of energy transfer between redox-active colloids using fluorescence microscopy, revealing non-linear electrofluorochromism and quantifying charge transfer kinetics, advancing understanding of colloidal energy transport.

Contribution

It introduces a novel method to directly observe and quantify energy transfer in redox-active colloids, providing new insights into colloidal charge transport mechanisms.

Findings

Redox-active colloids exhibit non-linear electrofluorochromism.

Charge transfer diffusion coefficient DCT was quantitatively extracted.

Real-time imaging of energy transfer in colloidal monolayers was achieved.

Abstract

Redox-based electrical conduction in nonconjugated polymers has been explored less than a decade, yet is already showing promise as a new concept for electrical energy transport. Here using monolayers and sub-monolayers of touching micron-sized redox active colloids (RAC) containing high densities of ethyl-viologen (EV) side groups, intercolloid redox-based electron transport was directly observed via fluorescence microscopy. This observation was enabled by the discovery that these RAC exhibit a highly non-linear electrofluorochromism which can be quantitatively coupled to the colloid redox state. By evaluating the quasi-Fickian nature of the charge transfer (CT) kinetics, the apparent CT diffusion coefficient DCT was extracted. Along with addressing more fundamental questions regarding energy transport in colloidal materials, this first real-time real-space imaging of energy transport within monolayers of redox-active colloids may provide insights into energy transfer in flow batteries, and enable design of new forms of conductive polymers for applications including organic electronics.