Impediment of Iron Corrosion by N,N′-Bis[2-hydroxynaphthylidene]amino]oxamide in 3.5% NaCl Solution

Abstract

Hydrazone [N,N′-bis[2-hydroxynaphthylidene]amino]oxamide] derived from the condensation of ethanedihydrazide with 2-hydroxynaphthalene-1-carbaldehyde was synthesized and assessed on the basis of elemental analysis (CHN) and spectral (IR, mass, 13C/1H NMR and UV-Vis) measurements. The influence of N,N-bis([2-hydroxynaphthylidene]amino)oxamide (HAO) in terms of the inhibition of iron corrosion in concentrated sodium chloride solution (3.5 wt.% NaCl) after various exposure periods was assessed. Numerous electrochemical and spectroscopic assessment techniques were performed. Cyclic potentiodynamic polarization experiments indicated that the presence of HAO and its increased concentration decreased the corrosion of iron in NaCl solution by decreasing the corrosion values, anodic and cathodic currents, and corrosion rate. The electrochemical impedance spectroscopy results showed that HAO molecules greatly increased the corrosion resistance. The chronoamperometric experiments performed at −475 mV (Ag/AgCl) revealed that the HAO molecules decreased the absolute currents and reduced the probability of the occurrence of pitting corrosion. The effect of HAO on the inhibition of iron corrosion was also confirmed through scanning electron microscopy micrographs and energy-dispersive X-ray profile analyses, which proved that the surface of the iron sample exposed to chloride solution alone was pitted, while the presence of HAO molecules reduced the severity of the pitting corrosion. The results confirmed that the presence of HAO molecules inhibits the corrosion of iron and this impact increased when the exposure time was increased to 48 h.

Influence of Zirconium on the Corrosion Passivation of Titanium in Simulated Body Fluid

“…The values of RCorr were also calculated from the corrosion parameters as reported in the earlier studies [16,[18][19][20]. The PCP curves represented in Figures 2 and 3 reveal that the cathodic current decreases towards the minimum values (where jCorr and ECorr obtained) due to the oxygen reduction [20,21]; The anodic reaction of Ti and Ti-Zr alloy starts with rising the current in the anodic side.…”

“…Obtaining βc and βa values were made via extrapolation of a tangent to the linearized current regions. The j Corr and E Corr values were obtained as reported before [16,[18][19][20]. The values of R P were calculated from of βc, βa and j Corr as follows [16,[18][19][20]:…”

“…The j Corr and E Corr values were obtained as reported before [16,[18][19][20]. The values of R P were calculated from of βc, βa and j Corr as follows [16,[18][19][20]:…”

“…As a result of these elements being presented, Table 2 summarizes their values. Similarly, the same circuit has been used for other materials [16,18,22]. The presence of a Q (CPEs) in a capacitive response system has been used to estimate deviations from ideality [23].…”

Alleviation of Iron Corrosion in Chloride Solution by N,N′-bis[2-Methoxynaphthylidene]amino]oxamide as a Corrosion Inhibitor

“…Herein, E Corr = the corrosion potential, j Corr = corrosion current density, β c = cathodic Tafel slope, β a = anodic Tafel slope, R P = polarization resistance, and R Corr = corrosion rate. Here, the values of j Corr and E Corr were drawn as in the previous works [1,3,5,[29][30][31][32][33][34]. The values of R P and R Corr were calculated from these relations [29][30][31][32][33][34]:…”