Electrodeposition of Cu-Reinforced Polyaniline Coating for Protection of AH36 Steel in Natural Seawater

Abstract

The marine environment is highly corrosive for mild and low alloy steels. This study aimed to enhance the corrosion resistance of the AH36 steel in a saline medium by coating it with a copper particles reinforced polyaniline (PANI) layer. PANI and Cu particles were grown on the steel surface by electrodepositing methods. Firstly, PANI was electropolymerized in the presence of oxalic acid, followed by the electrodeposition of Cu particles at different deposition times. The coating showed a well-distribution of Cu particles in the polymer matrix and excellent adhesion. Furthermore, the Cu particles and PANI-coated steels exhibited corrosion resistance significantly in the saline medium compared to the bare substrate and pristine PANI-coated samples. The improved corrosion protection of a Cu@PANI coating on the AH36 steel could contribute to forming a physical barrier by filling Cu particles on the PANI pores.

Recent progress of self-healing polyaniline organic composite coatings: active agents, methods and protection mechanism

“…Electrodeposition methods: a protective PANI-based film can be directly generated on the metal surface to be protected through electrochemical methods, including potentiostatic, chronoammetry, galvanostatic, cyclic voltammetry and pulsed electroposition, in an acidic solution of aniline (Yu et al, 2023;Chi et al, 2022;Chen et al, 2022;Gupta et al, 2021). Selfhealing PANI film was electrosynthesized on Al alloy by Kamaraj et al (2015) through the potentiostatic method.…”

Protective Properties of Calcareous Deposit Layer for Cathodically Polarized AH36 Steel in Natural Seawater

“…The AH36 structural steel plate used for cathode material was cut into the size of 150 mm × 100 mm × 3 mm with the compositions in wt% as shown in [27]. Before immersion and polarizing in seawater as a cathode, the plates were polished with SiC paper and cleaned in acetone.…”

“…Figure 3 presents the Tafel polarization curves of the AH36 bare steel and AH36 cathode in natural seawater for 1, 5, 9, and 12 months. After 9 months, the surface of the AH36 steel was covered under a passive film of corrosion products and biofouling [27][28][29]; the surface of the polarized AH36 steel was filled with white precipitates. The shift in the curves towards more positive potentials for the AH36 steel samples immersed in seawater indicates that passivation is established for the corroded AH36 steel containing corrosion products on the surface.…”