Preparation and electrochemical and electrochromic properties of wrinkled poly(N-methylthionine) film

•Poly(N-methylthionine) (PNMTh) film was prepared using cyclic voltammetry.•PNMTh film shows a micro-wrinkled surface with topographic features.•PNMTh film exhibits good electrochemical properties even in a basic solution up to pH 11.00.•PNMTh film displays a multicolor electrochromic behavior.

Poly(N-methylthionine), PNMTh, was prepared on the platinum foil using cyclic voltammetry. The pH of the monomer solution and applied oxidization potential strongly affected the polymerization rate and electroactivity of the polymer. The polymer electrosynthesized on the optimum conditions had a high electroactivity in 0.20 M phosphate buffer solution containing 0.25 M NaCl with pH ≤ 11.00. This is attributed to the presence of phenothiazine rings on the polymer chain. The polymer film displayed a multicolor electrochromic behavior when the applied potential was changed. The chemical structure of the polymer was characterized by UV–vis, infrared and X-ray photoelectron spectroscopies. The scanning electron microscopy image showed that the polymer film had a micro-wrinkled surface with topographic features.