ИСТИНА

The electrochemical polymerization of (3,4-ethylenedioxythiophene) (EDOT) was performed in the bath containing water-soluble polyelectrolytes of different chain flexibility. The potentiostatic (PS), galvanostatic (GS) and cyclic voltammetry regimes were used for EDOT electropolymerization. As polyelectrolytes flexible-chain poly-(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA) or poly(styrene sulfonic acid) (PSSA) and rigid-chain poly-4,4’-(2,2’- disulfoacid)-diphenylene-iso-phthalamide (iso-PASA) or poly-4,4’-(2,2’-disulfoacid)- diphenylene-tere-phthalamide (tere-PASA) and their sodium salts were chosen. These polyelectrolytes are characterized by high ionic conductivity that allowed performing EDOT electropolymerization without supporting electrolyte. It was found that EDOT PS-polymerization rate depends on the structure of polyelectrolyte used. The rate of PEDOT PS-synthesis was the highest in the presence of more hydrophobic PSSA (PSSNa) and the lowest when using more hydrophilic PAMPSA. The GS-synthesis of PEDOT-PSSA (PEDOT-PSSNa) complex proceeded at the lowest potential among studied cases. The differences between the rate and character of EDOT synthesis is likely to be explained by different distribution of EDOT in solution of polyelectrolyte of different hydrophobicity. The PEDOT films obtained were characterized by AFM-microscopy, Vis-NIR spectroscopy, cyclic voltammetry and Vis-NIR spectroelectrochemistry. It was found, that the electronic structure of PEDOT-PSSA and PEDOT-PAMPSA complexes was very similar and did not depend on whether polyacid was used or its salt. The intensive absorption in NIR-region was noticed for electronic spectra of PEDOT complexes with these flexible-chain polyelectrolytes. It means that in such conditions PEDOT is in its second oxidative conductive form (bipolarone form). On the contrary, the complexes of PEDOT-tere-PASA and PEDOT-iso-PASA were characterized by pronounced band at around 700 nm and low absorption above 900 nm. The absence of high absorption in NIR-region might be the sign of low degree of chain delocalization for latter complexes and they, therefore, seem to be less conductive. It is might be the result of rod-like chain conformation of these polyelectolytes that is insufficient for effective EDOT concentrating and growth of long chains. This work was supported by the Russian Foundation for Basic Research (grants No. 14-03-01137_а and 14-03-90413-Ukr_a), the Grant Council of the President of the Russian Federation (SP-2994.2015.1) and the Russian Science Foundation (grant No. 15-13-00170).