Poly(3,4-ethylenedioxythiophene) Electrosynthesis in the Presence of Mixtures of Flexible-Chain and Rigid-Chain Polyelectrolytes.

The electrochemical synthesis of poly(3,4-ethylenedioxythiophene) (PEDOT) was first carried out in the presence of mixtures of flexible-chain and rigid-chain polyacids and their Na-salts. Earlier on with the example of polyaniline, we have shown the non-additive effect of the rigid-chain component of polyacid mixtures on the electrodeposition of polyaniline films, their morphology and spectroelectrochemical properties. In this study, we confirmed the non-additive effect and showed that such mixed PEDOT-polyelectrolyte films possess unique morphology, spectroelectrochemical and ammonia sensing properties. The electrosynthesis was carried out in potential cycling, galvanostatic and potentiostatic regimes and monitored by in situ UV-Vis spectroscopy. UV-Vis spectroelectrochemistry of the obtained PEDOT-polyelectrolyte films revealed the dominating influence of the rigid-chain polyacid on the electronic structure of the mixed complexes. The mixed PEDOT-polyacid films demonstrated the best ammonia sensing performance (in the range of 5 to 25 ppm) as compared to the films of individual PEDOT-polyelectrolyte films.