Polyvinyl pyrrolidone oxime-TiO2-phenylalanine composite as a moderate corrosion resistant over low-carbon steel surface in marine environment: Computational, synthesis and electrochemical findings

Abstract

Corrosion resisting aptitude of modified polymer polyvinyl pyrrolidone as its oxime or PVPO after compositing with titanium dioxide (TiO₂) and phenylalanine (Phe) over frequently used low alloy steel (mild steel) or low carbon steel (LCS) surface is studied in the presence of saline water. Sol-gel method is adopted to synthesize PVPO-TiO₂-Phe, as a safe and influential corrosion inhibitor for mild steel in aqueous 3.5 % NaCl medium. The inhibition efficiency of the composite was explored using weight loss, electrochemical polarization and impedance spectroscopic techniques. Morphology of LCS substrate was tested by AFM and SEM techniques in presence and absence of the modified composite. Results showed that the trio combination prepared through sol-gel process provided appreciable protection, i. e. 85 % against corrosion in marine environment. Molecular Dynamics as well as the Density Functional Theory related studies are applied to correlate with the experimental inferences and consequent upon, these are found in fit relationship with the empirical data. A brief overview for protection mechanism that may be offered by the composite over the metal surface against the aggressive chloride ions is also comprehended.