ИСТИНА

The main advantage of the using of water-soluble polyelectrolytes during electrosynthesis of conducting polymers is the possibility to modify their structure with the purpose to change optical, electrochemical and spectroelectrochemical properties. The presence of polyelectrolytes during electrochemical synthesis: 1) reduces the oxidation potential of the monomer; 2) accelerates polymerization; 3) influences the structure and morphology of electrodeposited polymer films. The goal was to elucidate the role of polyelectrolyte during electrosynthesis of conducting polymers such as polyaniline (PANI), polypyrrole (PPy) and poly-(3,4-ethylenedioxythiophene) (PEDOT). The polymers were electrodeposited in potentiostatic, galvanostatic and cyclic voltammetry regimes in the presence of sulfonated polyelectrolytes with different structure and different molecular weight: poly(styrene-4-sulfonic acid) (PSSA), poly-(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA), and their sodium salts in the case of PPy and PEDOT. The course of electropolymerization was monitored by in situ Raman and UV-Vis spectroscopy. The films obtained were characterized by cyclic voltammetry, Vis-NIR and Raman spectroelectrochemistry. The crucial influence of the polyacid molecular weight on the synthesis kinetics and properties of the films obtained was observed for PANI-PAMPSA complexes and, to a lesser degree, for PANI-PSSA. On the contrary, no significant influence of molecular weight was found for PPy and PEDOT complexes. The electropolymerization rate of pyrrole and EDOT slightly depends on the polyelectrolyte cation (H+ or Na+). Specific influence of the nature of polyelectrolyte on conductive polymers is discussed considering peculiarities of the monomer distribution in the solution of polyelectrolyte with different conformational state, hydrophilicity and spatial distribution of sulfonic groups and protons (for PANI) in/near polyelectrolyte coils.