Diffusion-Cooperative Model for Charge Transport by Redox-Active Nonconjugated Polymers

Abstract

Charge transport processes in nonconjugated redox-active polymers with electrolytes were studied using a diffusion-cooperative model. For the first time, we quantitatively rationalized that the limited Brownian motion of the redox centers bound to the polymers resulted in the 10^3-4-fold decline of the bimolecular and heterogeneous charge transfer rate constants, which had been unexplained for half a century. As a next-generation design, a redox-active supramolecular system with high physical mobility was proposed to achieve the rate constant as high as in free solution system (>10⁷ M^-1 s^-1) and populated site density (>1 mol/L).