Thermally Stable and Solvent-Resistant Conductive Polymer Composites with Cross-Linked Siloxane Network

Doped conjugated polymers can present high electrical conductivity, but their stability against external stimuli such as heat, moisture, and solvent is often limited. Here, we report a design approach to render thermally and chemically stable conductive polymer composites consisting of 3,4-propylenedioxythiophene (ProDOT) and ethylenedioxythiophene (EDOT) based copolymers (CPs) and cross-linkable chlorosilane (C-Si). Through a sol–gel reaction, chlorosilane precursors form siloxane networks and simultaneously dope the polymers. Temperature-dependent in situ UV–vis absorption and conductivity characterization show that the conductive C-Si/CPs composites can retain their doped state at high temperature and in prolonged baking time. Specifically, the composites’ conductivity remains almost unchanged after 6 h and only slightly dipping to nearly 80% after 24 h of annealing at 80 °C in ambient air. They also exhibit excellent solvent resistance upon dipping into water and chloroform. This work reports a method of designing stable-doped polymer systems that can function under harsh conditions.