Comparatively Electrochemical Studies at Different Operational Temperatures for the Effect of Layered Silicate and Spherical Silica on the Anticorrosion Efficiency of PANI Nanocomposite Coatings

Abstract

In this paper, a series of PANI nanocomposites have been successfully prepared by in situ oxidative polymerization. The as-prepared PANI nanocomposites were subsequently characterized by WAXRD patterns and TEM. It should be noted that the nanocomposite coating containing 3 wt-% of organophilic clay loading was found to exhibit an observable enhanced corrosion protection on cold-rolled steel (CRS) electrode at higher operational temperature of 50 degrees C, which was even better than that of uncoated and electrode-coated with PANI or PANI nanocomposites with 3 wt-% of amino-modified silica nanoparticles alone at room temperature of 30 degrees C based on the electrochemical parameter evaluations (e.g., E(corr), R(p), I(corr), R(corr) and impedance). The vapor permeability property at three different operational temperatures of PANI and PANI nanocomposite membranes were investigated by vapor permeability analyzer (VPA). Effect of material composition on the molecular weight, optical properties and surface hydrophobicity of neat PANI and PANI nanocomposite, in the form of membrane and solution, were studied by gel permeation chromatography (GPC), ultraviolet-visible absorption spectra and contact-angle measurements, respectively. Finally, electrical conductivity at three different operational temperatures of PANI and PANI nanocomposite powder-pressed pellets was also investigated through the measurements of standard four-point-probe technique.