Electropolymerization and characterization of poly(N-methylaniline) and poly(N-butylaniline) in mixtures of aqueous and organic solvents

Electropolymerization of N-methylaniline (NMA) and N-butylaniline (NBA) was studied on glassy carbon and optically transparent tin oxide electrodes in mixtures of aqueous and organic solvents. Five different organic solvents, dimethyl formamide, dimethyl sulfoxide, tetrahydrofuran (THF), propylene carbonate (PC) and acetonitrile (ACN) were mixed with aqueous 1.0 M HClO4 solutions. Our results show that NMA and NBA can be electropolymerized in aqueous-organic solvent mixtures with maximum 30 and 50% (v/v) organic solvents, respectively. The choice of organic solvent strongly influences the film formation. With addition of 10-20% THF, ACN and PC to the aqueous polymerization solution, the film formation was highly improved. The poly(N-methylaniline) and poly(N-butylaniline) films were characterized with cyclic voltammetry, in situ UV-vis spectroscopy, size exclusion chromatography and with electrical conductivity measurements.