Preparation of micropatterned polyaniline thin films with enhanced electrochromic properties by electrostatic field-assisted potentiostatic deposition

• Polyaniline micropatterns formed by electrostatic field-assisted electrodeposition.
• Mechanism of the electrostatic field-assisted electrodeposition was proposed.
• Micropatterned polyaniline thin films showed enhanced electrochromic performances.
• Micropatterned polyaniline thin films havesmaller charge-transfer resistances.

Micropatterned polyaniline (mPani) thin films on indium tin oxide (ITO) conducting substrates are prepared by the electrostatic field-assisted potentiostatic deposition (ESaPD) and their electrochromic (EC) properties are investigated in this study. The mPani thin films can be directly electrodeposited onto the ITO substrates under the influence of a patterned electrostatic field induced by a micropatterned electrostatic film through contact electrification. It is found that the mPani thin film has faster coloring/bleaching responses, small enhancement in transmittance modulation ability and higher coloration efficiency than the non-patterned Pani thin film prepared with the same deposition time. Electrochemical impedance spectroscopy analysis indicates that the charge-transfer resistance of the mPani thin film is smaller than that of the non-patterned Pani thin film, and which could be the reason for the enhancement of the EC properties of the mPani thin film.