Origin of the material dependence of temperature coefficient of redox potential in conjugated polymers

The thermal coefficient alpha (=dV/dT) of the redox potential (V) is an important physical parameter for thermal energy harvesting. To clarify the microscopic origin of alpha in conjugated polymers, we compared alpha and the physical quantity obtained by a quantum chemistry calculation in typical polymers with small monomer molecular weight. We observed a strong correlation between alpha and the number (N-active) of the active atom, which is defined as the atom whose variation of the Mulliken charge (Delta q) at the oxidation process is beyond a threshold (Delta q(th)). We interpreted the material dependence of alpha in terms of N-active, because active atoms have a significant effect on the configuration entropy of the surrounding solvent molecules.

Automated summary

The thermal coefficient alpha of the redox potential is crucial for thermal energy harvesting. A strong correlation has been observed between alpha and the number of active atoms (N-active) in conjugated polymers, which significantly impact the configuration entropy of surrounding solvent molecules.