A comparative study of polymer films on steel from ionic liquid and aqueous solution

Electrosynthesis of polypyrrole coatings on steel has been investigated in ionic liquid, 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide (EMITFSI). The electrical conductivity, morphology, adhesion, permeability and the protection efficiency have been interpreted. For this purpose, SEM and ATR-FTIR spectroscopy measurements, electrochemical impedance spectroscopy (EIS), temperature dependent potentiodynamic polarization and electrochemical noise measurements were utilized. Ionic liquid synthesis environment offers a polymer film with low permeability and better electrical conductivity. However, it has a substantial drawback like poor adhesion on steel, when compared to coatings obtained from aqueous solution. In order to combine superiorities of different synthesis conditions bilayer coating system has been prepared and showed that this coating has better coating properties.