Design of a Functional Active Epoxy Coating for Anticorrosion Performance Using SiO2 Nano-Conductive Polyaniline Nanoparticles in Aluminum Blends of Helicopters

Abstract

In this study, polyaniline (PANI) nanocomposites/silica (SiO2) nanoparticles are used in epoxy to create smart anticorrosive coatings for the alloy used in helicopters. SiO2 was synthesized by a sol–gel method with tetraethyl orthosilicate. Then, PANI/SiO2 nanocomposites were formed by the electrostatic method. Various tests, including Fourier-transform infrared, ultraviolet–visible spectroscopy, x-ray diffraction, thermo-gravimetric analysis and field-emission scanning electron microscopy, have been performed for characterization of the nanocomposites, and the results indicate that the synthesis of these nanocomposites has been completed. Then, 1\xa0wt.% of PANI/SiO2 nanocomposite was added into epoxy resin and cured by polyamine hardener. Epoxy/PANI/SiO2 coatings with 30-µm thickness were tested on the alloy of the helicopter body. The atomic weight fraction of the helicopter alloy was determined by the inductively-coupled plasma emission test. The results indicate that aluminum constitutes 98% of the alloy. Finally, the analysis of the sealed coatings by electrochemical impedance spectroscopy and salt spray tests have demonstrated that epoxy/polyaniline/silica nanocomposites significantly increase the anticorrosive properties of the epoxy.