High corrosion protective behavior of water-soluble conducting polyaniline–sulfonated naphthalene formaldehyde nanocomposites on 316L SS

Abstract

In this paper, water-soluble conducting polyaniline–sulfonated naphthalene formaldehyde nanocomposites (PAni–SNF NCs) were successfully synthesized by a one-step in-situ polymerization method. The structural characterization of the synthesized PAni–SNF NCs was confirmed by Fourier transform-infrared spectroscopy (FT–IR), Ultraviolet-visible spectroscopy (UV–Vis), Proton nuclear magnetic resonance spectroscopy (1H NMR), Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX), Dynamic light scattering (DLS), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Conductivity measurements, Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), and Cyclic voltammetry (CV). The corrosion protective behavior of 316L stainless steel (316L SS) in 1 M HCl was examined using electrochemical measurements and weight loss methods at various PAni–SNF NCs. The inhibition efficiency of PAni–SNF NCs was found to 97.9% and 99.3% in the case of PANS-3 and PANS-10 NCs at the optimum concentration of 50 ppm. The potentiodynamic polarization method demonstrated that PAni−SNF NCs acted as a mixed-type inhibitor in both studied NCs. Moreover, adsorption of PAni−SNF NCs inhibitor on the 316L SS surface followed the Langmuir isotherm model. The present report provides extremely significant findings in preparing and designing novel and sustainable corrosion inhibitors with high inhibition efficiency.