Correction: Thiophene derivatives as corrosion inhibitors for 2024-T3 aluminum alloy in hydrochloric acid medium.

[This corrects the article DOI: 10.1039/D2RA00185C.].

Thiophene derivatives as corrosion inhibitors for 2024-T3 aluminum alloy in hydrochloric acid medium.

Thiophene derivatives, namely (E)-thiophene-2-carbaldehyde oxime (OXM) and (E)-5-(thiophen-2-yl)-1H-tetrazole (TET), were synthesized and characterized via 1H and 13C NMR. Furthermore, their inhibitory property for AA2024-T3 in 1 M HCl solution was investigated via electrochemical impedance spectroscopy and potentiodynamic polarization at 293 K, together with DFT/B3LYP-based calculations. Numerous global and local descriptors of reactivity such as EHOMO, ELUMO, energy gap, electronegativity (χ), hardness (η), and frontier molecular orbital repartitions were investigated to describe the reactivity of each molecule. Alternatively, Monte Carlo simulations were performed under the solvation condition on the Al (111) surface to understand the adsorption behavior of the as-studied inhibitors deeply. The inhibition efficiency increased with an increase in the inhibitor concentration, achieving maximum values of 94.0% and 96% at 10-3 M, respectively. The polarization curves showed that the examined compounds act as mixed-type inhibitors. In addition, the adsorption of these compounds obeyed the Al Awady, Flory-Huggins and Temkin isotherms. The surface characterization analysis via SEM/EDX confirmed the presence of a barrier layer covering the aluminum surface. The experimental inhibition efficiencies were correlated with global descriptors, which confirmed that this theoretical study is useful for the protection of aluminum alloy metal in an acidic medium.

Novel triazole derivatives as ecological corrosion inhibitors for mild steel in 1.0 M HCl: experimental & theoretical approach.

The present paper illustrates the investigation of two novel ecological triazole derivative corrosion inhibitors, namely ethyl 2-(4-phenyl-1H-1,2,3-triazol-1-yl) acetate [Tria-CO2Et], and 2-(4-phenyl-1H-1,2,3-triazol-1-yl) acetohydrazide [Tria-CONHNH2]. The studied inhibitors were investigated against the corrosion of mild steel in 1.0 M HCl solution using different electrochemical techniques. Potentiodynamic polarization experiments indicated that the [Tria-CO2Et], and the [Tria-CONHNH2] acted as mixed type inhibitors. Electrochemical impedance spectroscopy measurements revealed that both inhibitors presented a high inhibition performance, achieving an inhibition efficiency of 95.3% for [Tria-CO2Et] and 95.0% for [Tria-CONHNH2] at a concentration of 1.0 × 10-3 M. Based on the Langmuir isotherm model and the activation parameters, these triazole derivatives were adsorbed onto a steel surface by physical and chemical bonds. Density functional theory based on B3LYp6-311G(d,p) was also carried out to correlate the inhibition efficiencies obtained experimentally with the theoretical descriptors of the studied molecular structures.

Effect of 1-(3-phenoxypropyl) pyridazin-1-ium bromide on steel corrosion inhibition in acidic medium.

The effect of 1-(3-phenoxypropyl) pyridazin-1-ium bromide, a new pyridazinium derivative, on steel corrosion in a HCl (1 M) solution was analyzed using electrochemical impedance and XPS spectroscopy. Experimental results indicated that the inhibition efficiency increased with an increase in an inhibitor concentration. Electrochemical impedance spectroscopy measurements revealed that an increase in the immersion time of steel in an acidic medium from 1 to 12 h and further to 24 h decreased the charge transfer resistance (Rct) and thus decreased the inhibition efficiency. The SEM and XPS analyses linked the inhibition effect to the adsorption of the inhibitor (1-(3-phenoxypropyl) pyridazin-1-ium bromide) on the steel surface.

Desferrioxamine enhances hypoxic ventilatory response and induces tyrosine hydroxylase gene expression in the rat brainstem in vivo.

The iron chelator desferrioxamine (DFO) induces accumulation of the hypoxia-inducible factor (HIF-1), a transcription factor that up-regulates genes involved in adaptative responses to hypoxia. This property makes DFO a potential neuroprotector against hypoxic stress. We investigated in rats the effects of DFO on the ventilatory response to mild hypoxic tests and the expression of tyrosine hydroxylase (TH), a target gene of HIF-1. Two protocols were used, the first with repeated injections of 50 mg/kg DFO every 2 days during a 2-week period. This was aimed at define the time course of the ventilatory responses to a hypoxic test. In the second protocol, rats were given a single injection of 300 mg/kg DFO. Every day over 4 days, the hypoxic ventilatory response was recorded before the animal was sacrificed, and Western blot analysis of TH in the dorsal brainstem cardiorespiratory area was performed. DFO produced a delayed increase in the hypoxic ventilatory response, which appeared in the same time window as TH up-regulation (2-3 days after the bolus injection of DFO). This delay suggests a genic effect of the drug that improves the ventilatory response to hypoxia.