Silver Nanoparticles Intercalated Polyaniline Composites for High Electrochemical Anti-Corrosion Performance in 6061 Aluminum Alloy-Based Solar Energy Frameworks

In this work, we report on polyaniline (PANI)–silver nanoparticles (AgNPs) coatings prepared by in-situ polymerization technique. These composites show an excellent corrosion resistance behavior in aggressive environments much superior to PANI. The corrosion studies were carried out on 6061 aluminum alloy substrates coated with PANI-AgNPs composites with different concentrations of silver nanoparticles. The PANI-AgNPs composites were characterized by Scanning and Transmission electron microscopes (SEM/TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Thermogravimetric analysis (TGA). The conductivity of these composites strongly depends on AgNPs concentration with percolation maxima at 20 wt% of AgNPs in PANI. The composite coatings were evaluated for anti-corrosion performance by using standard corrosion testing method, open-circuit potential analysis, potentiodynamic polarization curve, and electrochemical impedance spectroscopy. The increase in diffusion barrier, prevention of charge transport by the AgNPs, redox properties of polyaniline as well as the large surface area available for the liberation of dopant due to nano-size additive appear to be associated with the exceptional improvement in anti-corrosion performance of elaborated coatings. Due to ease of preparation, better thermal stability, enhanced conductivity, and excellent corrosion inhibition properties, this PANI-AgNPs composite could be used as a potential anti-corrosion coating material in protecting aluminum infrastructures.