Growth of N-substituted polypyrrole layers in ionic liquids: Synthesis and its electrochromic properties

A new series of pyrrole family, N-substituted phenyl attached alkyl at the ortho, meta and para position were synthesized by a straight forward method and were exploited as an innovative monomer for electroactive polymers. Ionic liquids were employed as a medium for electro-polymerization of these monomers to obtain N-(methyl)phenyl polypyrroles. N-substituted polypyrroles show different morphologies and conductivity according to position of methyl group on the benzene ring and synthesis medium. The electrical conductivity value varies with the position of methyl group and was >10−5 S/cm, higher than the sample obtained from conventional media. The resulting polymer films were characterized by FT-IR and UV–Vis spectroscopy, contact angle measurements, cyclic voltammetry and scanning probe microscopic technique along with their electrochromic behavior.