Morphology of a Self-Doped Conducting Oligomer for Green Energy Applications

Juan Felipe Franco-Gonzalez (1, 2) , Eleni Pavlopoulou (3, 4) , Eleni Stavrinidou (1, 2) , Roger Gabrielsson (1, 2) , Daniel Simon (1, 2) , Magnus Berggren (1, 2) , Igor V Zozoulenko (1)

1 Department of Science and Technology [Linköping]
2 Department of Science and Technology - Laboratory of Organic Electronics [Norrköping, Sweden]
3 LCPO - Laboratoire de Chimie des Polymères Organiques
4 Team 4 LCPO : Polymer Materials for Electronic, Energy, Information and Communication Technologies

A recently synthesized self-doped conducting oligomer, salt of bis[3,4-ethylenedioxythiophene]3thiophene butyric acid, ETE-S, is a novel promising material for green energy applications. Recently, it has been demonstrated that it can polymerize in vivo, in plant systems, leading to a formation of long-range conducting wires, charge storage and supercapacitive behaviour of living plants. Here we investigate the morphology of ETE-S combining the experimental characterisation using Grazing Incidence Wide Angle X-ray Scattering (GIWAXS) and atomistic molecular dynamics (MD) simulations. The GIWAXS measurements reveal a formation of small crystallites consisting of p-p stacked oligomers (with the staking distance 3.5Å) that are further organized in h00 lamellae. These experimental results are confirmed by MD calculations, where we calculated the X-ray diffraction pattern and the radial distribution function for the distance between ETE-S chains. Our MD simulations also demonstrate the formation of the percolative paths for charge carriers that extend throughout the whole structure, despite the fact that the oligomers are short (6-9 rings) and crystallites are thin along the p-p stacking direction, consisting of only two or three p-p stacked oligomers. The existence of the percolative paths explains the previously observed high conductivity in in-vivo polymerized ETE-S. We also explored the geometrical conformation of ETE-S oligomers and the bending of their aliphatic chains as a function of the oligomer lengths.

Domaines: Polymères

Juan Felipe Franco-Gonzalez, Eleni Pavlopoulou, Eleni Stavrinidou, Roger Gabrielsson, Daniel Simon, et al.. Morphology of a Self-Doped Conducting Oligomer for Green Energy Applications. Nanoscale, 2017, 9 (36), pp.13717-13724. ⟨10.1039/x0xx00000x⟩. ⟨hal-02888903⟩