The electrochemical synthesis and corrosion behaviour of TiO2/poly(indole-co-aniline) multilayer coating: Experimental and theoretical approach

Abstract

The aim of this study was to protect stainless steel against corrosion via poly (indole-co-aniline) with the help of titanium dioxide pre-coating. Different monomer ratios (1:1 and 1:9) wereapplied in order to determine the suitable chain composition to synthesize the copolymer in lithiumperchlorate containing acetonitrile. The structures, morphologies, electrochemical properties andcorrosion resistances of the mono and multi-layer coatings were investigated by Fourier-transform infrared spectra, scanning electron microscope, energy dispersive X-ray spectrometer,electrochemical impedance spectroscopy and anodic polarization. Furthermore the geometric struc-ture and electronic properties of indole, aniline, and indole-co-aniline (dimmer) molecules have beeninvestigated by quantum calculations. The results indicated that corrosion protection of copolymerswas increased via titanium dioxide pre-coating. The 1:1 copolymer coating showed better corrosionprevention than 1:9 coating. The correlation was determined between experimental and theoreticalparameters.