Inhibitive effect of sodium (E)-4-(4-nitrobenzylideneamino)benzoate on the corrosion of some metals in sodium chloride solution

Abstract

The inhibition performance of a novel anionic carboxylic Schiff base, sodium (E)-4-(4nitrobenzylideneamino)benzoate (SNBB), was investigated for various metals, namely low carbon steel F111, pure iron and copper, in neutral 10 mM NaCl solution. Potentiodynamic polarization, scanning vibrating electrode technique (SVET), quantum chemical (QC) calculation, and molecular dynamics (MD) simulation were employed. The potentiodynamic polarization data showed that SNBB acts as an effective corrosion inhibitor for both iron and F111 steel, but it is not effective for the copper. In situ spatially-resolved SVET maps evidenced a major change in surface reactivity for Fe and F111 steel immersed in 10 mM aqueous solution in the absence and in the presence of SNBB. Featureless ionic current density distributions were recorded in the presence of SNBB at both their spontaneous open circuit potential (OCP) and under mild anodic polarization conditions, while major ionic flows were monitored above the metals in the absence of SNBB. On the basis of computer simulations, it is proposed that SNBB produces a stable chelate film on iron and steel surfaces that accounts for the good corrosion inhibition efficiency observed. The different inhibition efficiencies of SNBB molecules on the iron and copper was attributed to the special chemical structure of SNBB molecule and its different chelation ability with the released metal ions on the metal surface. The QC calculations also confirmed the high corrosion inhibition efficiency of SNBB. The MD simulation indicated higher binding energy of SNBB on iron surface compared to that of copper surface. The interaction mode of SNBB on iron and F111 steel surfaces corresponds to a mixed chemical and physical adsorption, and it obeys the Langmuir isotherm.

Theoretical and experimental studies of a new aniline derivative corrosion inhibitor for mild steel in acid medium

“…The plot is presented in Figure . The Langmuir theory supposes a monolayer adsorption of molecules on the solid surface without interaction between neighboring active sites …”

Experimental characterization, machine learning analysis and computational modelling of the high effective inhibition of copper corrosion by 5‐(4‐pyridyl)‐1,3,4‐oxadiazole‐2‐thiol in saline environment

“…MD simulation studies were performed using Material Studio 6.0 software (Accelrys Inc., San Diego, CA, USA) to learn more about the adsorption of the inhibitor molecules on the metal surface at the molecular level. The MD simulations were carried out by taking single crystal Cu (111) surface (the most densely packed and therefore the most stable [52]) in a simulation box of dimensions 3.58 nm × 3.58 nm × 3.61 nm with periodic boundary conditions to model a representative part of the interface devoid of any arbitrary boundary effects. The appropriate surface was first cleaved from pure Cu crystal and relaxed by minimizing its energy using molecular mechanics.…”

“…Computational methods using DFT theory are powerful tools for quantifying the structural features and parameters of the electronic structure of chemical compounds [52,82]. Recently, quantum chemistry has become widely used in the design and development of novel high performance corrosion inhibitors, as well as to analyse the characteristics of the interaction mechanism between the inhibitor and the metal surface mechanism, and to elucidate the structural nature of the inhibitor in the corrosion process [52,81,83].…”

Pitting corrosion inhibition of 304 stainless steel in NaCl solution by three newly synthesized carboxylic Schiff bases

“…The breakdown starts at the pores in the passive film of SS giving rise to strong local release of Fe cations. Since the SNBB molecule is a strong chelator and can form stable chelates with the Fe(II) ions [33], the SNBB molecules may migrate to these sites to react with the Fe ions and form chelates (with stability constants logK1 = 6.3125 and logK2 = 5.2610) which will deposit finally at these sites and eventually plug them [22,52].…”

“…Schiff bases and their complexes are non toxic and they find wide application in food industry, dye industry, analytical chemistry, catalysis, medicine, fungicidal, agrochemical and biological fields [30][31][32]. Schiff base derivatives with additional heteroatoms, such as N and O, and aryl groups, have also been used as corrosion inhibitors [14,17,33], but up to now, their application as pitting corrosion inhibitors has not been explored.…”