Sabine Ludwigs1

1, University of Stuttgart, Stuttgart, , Germany

This talk will give an overview about our recent activities on electronic and ionic conductivity in conjugated and redox polymer thin films with different molecular architectures. Preparation of films is done either by electropolymerization or solution deposition followed by morphology tuning, e.g. by solvent vapor annealing.[1]
We are particularly interested in three-dimensional architectures based on branched monomers such as terthiophenes (3T) or triphenylamines (TPA). TPA redox moieties are useful to allow for electrochemical or chemical crosslinking of as-deposited films. Both, with TPA redox polymers[2] and with polymers which bear TPA as pending redox moieties of linear polythiophenes[3] we could perform successful crosslinking and simultaneous doping of polymer films. The films provide very high stabilities with high electronic conductivities as evidenced by cyclic voltammetry coupled with in-situ conductance measurements and four-point-probe measurements. In the case of 3T we have reported on homopolymer and copolymer films of 3T and ethylenedioxythiophene which allow polymer-analogous reactions to induce ionic functionalities, thereby creating branched conjugated polyelectrolyte films.[4], [5]
To get a better understanding on mixed conductivity in polymer films, we have recently performed a study on electronic and ionic conductivity of linear conjugated polyelectrolytes by impedance spectroscopy and dc-measurements.[6] The clear dependence of the conductivities as function of humidity and degree of doping will be discussed in the talk in more detail.

[1] G.L. Schulz, S. Ludwigs, Adv. Funct. Mater. 27, 2017, 1603083.
[2] O. Yurchenko, J. Heinze, S. Ludwigs, Chem. Phys. Chem. 11, 2010, 1637.
[3] P. Reinold, K. Bruchlos, S. Ludwigs, Polymer Chemistry 8, 2017, 7351.
[4] M. Goll, A. Ruff, E. Muks, F. Goerigk, B. Omiecienski, I. Ruff, R.C. González-Cano, J.T. Lopez Navarrete, M.C. Ruiz Delgado, S. Ludwigs, Beilstein J. Org. Chem. 11, 2015, 335.
[5] T.V. Richter, C. Bühler, S. Ludwigs, J. Am. Chem. Soc. 134, 2012, 43.
[6] R. Merkle, P. Gutbrod, P. Reinold, M. Katzmaier, R. Tkachov, J. Maier, S. Ludwigs, Polymer 132, 2017, 216.