MOSAIC-EP: Role of Molecular Architecture and Self-Assembly in Charge Transport in Electroactive Polymers

• Applicant: Professor Dr. Marcus Müller
• Subject Area: Experimental and Theoretical Physics of Polymers ; Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry ; Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 571111721

This project will theoretically address electron-transport processes in redox-active polymers, which are relevant materials for biosensors and energy-storage applications. By leveraging and synergistically combining the expertise of the Argentinean and German groups, we will address this problem at different length scales, using single-site and coarse-grained simulation models. The single-site model represents every redox site by a simulation bead, employing LAMMPS. The coarse-grained model maps multiple redox sites, λ, into a single coarse-grained segment and will be based on the Single-Chain-in-Mean-Field algorithm. This will grant us access to device-relevant length scales (micrometer). We will devise two different strategies (RedOx Monte-Carlo algorithm and Master-Equation approach) to couple electron-hopping events between redox sites with the dynamics of the polymers. These new approaches will be used to address how the chemical architecture of the polymer (e.g., linear vs branched), its inter- and intramolecular interactions, and its self-assembly behavior (i.e., domain formation in redox-active block copolymers) affect the efficiency of diffusive transport of redox charge in the semi-dilute and concentrated regimes. Unlike previous work in the field, our simulation set-up will explicitly incorporate the electrodes that inject redox charge into the system, thereby allowing the exploration of the role of the polymer-electrode interactions and the introduction of surface modifiers (such as polymer brushes) on the efficiency of electron transfer at the polymer-electrode interface. Our simulations will predict the diffusion coefficient for redox-charge transport, D_app, and the heteroge- neous electron-transfer rate constant, k_0 – two relevant parameters that can be measured experimentally. Currently, the field relies on approximate, analytical models to predict these parameters. Our simulations will serve to test their validity and range of applicability. Ultimately, our aim is pioneering new design strategies that can optimize the properties of redox polymers for their different uses, and drive advancements at the interface of theoretical insights and technical applications.

• DFG Programme: Research Grants
• International Connection: Argentina
• Cooperation Partners: Dr. Yamila Perez Sirkin; Professor Dr. Mario Tagliazucchi