Inhibitive effect of 1,3,4-thiadiazole-2,5-dithiol on copper corrosion in chloride media

Abstract

Corrosion inhibition of copper by 1,3,4-thiadiazole-2,5-dithiol (DMTD) was investigated in 0.1 M NaCl solution using electrochemical methods, surface and solution analysis. Polarization tests results showed that DMTD inhibits efficiently copper corrosion, prevents oxide formation and revealed a marked effect of mixed inhibition after 1 h and 24 h immersion. Electrochemical impedance spectroscopy (EIS) measurements corroborate these results and indicate that the value of polarization resistance increased with DTMD concentration for 1 h immersion time. Addition of 10-2 M DMTD in the test solution exhibited a maximum inhibitive efficiency of 97% up to 24 h immersion. Surface analysis techniques were conducted on copper specimens after 24 h immersion in 0.1 M NaCl solution. SEM/EDX results confirmed that DMTD forms an adsorbed protective layer on copper surface which was found to be hydrophobic as indicated by contact angle (CA) measurements. These results were further confirmed by XRD patterns which indicated the lack of crystallized corrosion products. Cland Cu 2+ ions concentrations in the solution, after 30 days immersion of copper sheet in 0.1 M NaCl solution with and without 10-2 M DMTD, were determined by ionic chromatography (IC) and conducted by Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) respectively. The results showed that without DMTD Clconcentration decreases, while Cu 2+ one increases due to corrosion process. In contrast, in the presence of 10-2 M DMTD chloride ions concentration remained practically unchanged (0.099 mol/L) and Cu 2+ concentration is quite low.

Oxygen reduction reaction kinetics on pure copper in neutral sodium sulfate solution

“…Regarding the fact that a CPE is described as a parallel combination of a resistor and a pure capacitor, Q may be replaced by the values of capacitance calculated using Brug's formula described by Eqs. (8-9) [47][48][49]: The values of α dl ranged from 0.81 to 0.85 and the double-layer capacitances from 58 to 79 µF cm −2 . From impedance spectra recorded at 1000 rpm, the dependence of R ct and R d on potential is recapped in Table 2.…”

Recycling of Expired drug (levofloxacin hemihydrate) as a potential Eco-friendly Inhibitor for Copper in Synthetic Acid Rain Solution (SAR)

“…Consequently of the surface's roughness and inhomogeneity, frequency dispersion causes suppressed semicircles (Echihi et al, 2019). Concurrently, when the concentration grows, the diameter of the Nyquist plots expands, signifying that copper is better shielded at greater concentrations (Lamaka et al, 2007).…”

“…The gradual substitution of H 2 O molecules is likely responsible for the increase in both R ct and the inhibition activity η% (Quartarone et al, 2008;Sherif et al, 2008) and hostile ions by adsorbing LFH molecules to a Cu surface, resulting in the formation of an adherent layer. Therefore, it is possible to infer that a reduction in double-layer thickness results from the produced film's increasing coverage of the copper substrate (Echihi et al, 2019;Tasić et al, 2018).…”