Although many different human activities such as the oil and gas sector, mineral production, utilities, transportation, etc. depend on the utilization of steel and its alloys, they are highly susceptible to corrosion, especially in acidic media. Hence, processing entails substantial material expenditures due to metal losses. In this regard, the inhibitory characteristics of the synthetic heterocyclic derivative (3aR,7S,7aS)-4,5,6,7,8,8-hexachloro-1,3- dioxo-1,3,3a,4,7,7a-hexahydro-2H-4,7-methanoisoindol-2-yl)benzenesulfonamide (MBSI) was studied against corrosion of C-steel in 0.5 M H2SO4 at 25-55 ◦C. The structure of the synthesized molecule was confirmed by FTIR, 1 H-NMR, 13C-NMR, and MS. Weight-loss, potentiodynamic polarization, electrochemical impedance spectroscopy, electrochemical frequency modulation measurements as well as theoretical analyses were employed in this investigation. The results showed that the investigated MBSI compound functions as an efficient inhibitor with a physical adsorption nature on the surface of carbon steel. MBSI concentration causes the inhibition efficiency to rise, reaching a maximum of 94% for the steel alloy corrosion at 37 × 10− 6 M and 25◦C. The synthesized compound was suggested to act as a mixed-type inhibitor. SEM surface analysis showed the construction of a protective layer at the carbon steel surface. DFT-based quantum chemical indices provided more insight into the inhibitory mechanism. Molecular dynamics (MD) simulations were also applied to predict the conformational adsorption change of the inhibitor on the iron surface. In addition, thermodynamic and kinetic parameters were calculated. The experimental results are largely consistent with the theoretical results.

In this report, N-benzylhydrazinecarbothioamide (BHCTA) was investigated as an organic inhibitor for the corrosion of copper substrate in 3.5 wt.% sodium chloride electrolyte at 298 K. The inhibition efficiency of BHCTA was examined using electrochemical, chemical and theoretical tools. The gained outcomes indicated a supreme inhibition efficiency of BHCTA which exceeded 95 % upon addition of 1.00 mM of BHCTA. Such supreme efficiency was discussed on the basis of decisive adsorption of BHCTA molecules on the copper substrate that hinders concurrently the anodic oxidation and cathodic reduction reactions progressions. The adsorption of BHCTA on the copper surface was discovered to obey Langmuir isotherm. The resulting value of Gads0 = −35.7 kJ mol−1 indicates that BHCTA molecules adsorb on the copper surface through a spontaneous mix of physisorption and chemisorption processes. A scanning electron microscope was used to examine the effect of BHCTA adsorption on the morphology of the copper surface. Theoretical calculations showed that BHCTA has good adsorption properties on Cu substrate. There is a good consistency between the applied experimental and theoretical tools, confirming the validity of the gained outcomes.

The use of corrosion inhibitors is considered as the supreme dominant approach to control the damage of metallic corrosion. Organic dyes are extensively employed as inhibitors for the corrosion of various metals and alloys in diverse media. Herewith, Alcian blue dye (ABD) was selected to investigate its inhibitive characteristics against the corrosion of copper in 1.0 M H2SO4 solution at 298 K. This investigation was monitored by various chemical, electrochemical, and spectroscopic techniques. The results indicated that the examined dye is a proficient inhibitor for the corrosion of copper in 1.0 M H2SO4 solution and its inhibition efficiency (% IE) was increased with augmenting its concentration and diminished with rising medium temperature. The high anticorrosive ability of the selected dye was attributed to its adherent adsorption of such dye on the Cu surface and follows Langmuir isotherm. Thermodynamics and kinetics of corrosion of copper and its inhibition by the examined dye were inspected. The mechanisms of copper corrosion in H2SO4 solution and its inhibition by ABD were proposed. The obtained results illuminated that the examined dye acts as a mixed-type inhibitor with cathodic precedence. Finally, all gained results with respect to % IE values of the dye were compared and designated a good harmony between all applied techniques.

In this paper, the degradation of fluconazole drug (Flz) was explored kinetically utilizing permanganate ion [MnO4 −] as an oxidant in different acidic environments, namely sulfuric and perchloric acids at various temperatures. Stoichiometry of the reactions between Flz and [MnO4 −] in both acidic environments was attained to be 1.2 ± 0.07 mol. The kinetics of the degradation reactions in both cases were the same, being unit order regarding [MnO4 −], fewer than unit orders in [Flz], and fractional second orders in acid concentrations. The rate of oxidative degradation of fluconazole in H2SO4 was higher than that in HClO4 at the same investigational circumstances. The addition of small amounts of Mg2+ and Zn2+ enhanced the degradation rates. The activation quantities were evaluated and debated. The gained oxidation products were characterized using spot tests. A mechanistic approach for the fluconazole degradation was suggested. Finally, the rate law expressions were derived which were agreed with the acquired outcomes. The rates of degradation for various [Flz] were mathematically modeled using the response surface methodology (RSM). The RSM model’s conclusions and the experimental findings are in agreement. The oxidative degradation mechanism of Flz using density functional theory (DFT) was performed. The fluconazole drug degrades in acidic settings, protecting both the environment and human health, according to a method that is easy to use, powerful, inexpensive, practical, affordable, and safe.

Due to the unique properties of steel, including its hardness, durability, and superconductivity, which make it an essential material in many industries, it lacks corrosion resistance. Herewith, two novel triazole-thione Schiff bases, namely, (E)-5- methyl-4-((thiophen-2-ylmethylene)amino)-2,4-dihydro-3H-1,2,4-triazole-3-thione (TMAT) and (E)-4-(((5-(dimethylamino)thiophen-2-yl)methylene)amino)-5-methyl2,4-dihydro-3H-1,2,4-triazole-3-thione (DMTMAT), were synthesized and characterized. The corrosion inhibition (CI) ability of these two molecules on carbon steel in an aqueous solution of 1 M HCl as well as their interaction with its surface was studied using a number of different techniques. The results confirmed that the CI capability of these organic molecules depends on their strong adsorption on the metal surface and the formation of a protective anticorrosion film. Weight loss tests revealed that the inhibition efficiencies of TMAT and DMTMAT were 91.1 and 94.0%, respectively, at 1 × 10−3 M concentrations. The results of electrochemical impedance spectroscopy (EIS) indicated that there was a direct relationship between the inhibitor concentration and the transfer resistance. Potentiodynamic polarization (PDP) experiments have proven to be mixed-type inhibitors of C-steel in aqueous hydrochloric acid solution and follow the Langmuir adsorption isotherm model. Several thermodynamic and kinetic parameters were calculated. The negative values of the adsorption-free energy are −36.7 and −38.5 kJ/mol for TMAT and DMTMAT, respectively, confirming the spontaneity of the adsorption process. The MD simulation study’s findings show that the inhibitor molecules are nearly parallel to the metal surface. The interaction energy calculated by the MD simulation and the inhibitory trend are the same. The practical implementation is consistent with what the computer models predicted.

Kinetics of isosorbide (S) oxidation by Ce(IV) in aqueous HClO4 medium has been examined via spectrophotometric technique at fixed ionic strength and temperature. The reaction showed a 1: 2 stoichiometry (S: Ce(IV)). The reaction was studied under pseudo-first order conditions. The dependency of the rate of oxidation reaction on the reactants’ concentrations showed that the reaction was first order in [Ce(IV)], whereas in both [H+] and [S], its order was lower than unity. The oxidation rate was directly proportional to ionic strength as well as dielectric constant of the reaction medium. However, it should be mentioned that adding Ce(III) had remarkably not affect the rate. The isosorbide oxidation product was recognized as (1S,4S,5R)-4-hydroxy-2,6-dioxabicyclo[3.3.0]octan-8-one). A mechanistic scheme for oxidation coherent with the observed kinetics was proposed. The rate-law expression was derived which was agreed with the acquired outcomes. The calculated activation quantities recommended construction of a rigid intermediate through the reaction and such process was endothermic and non-spontaneous.

Magnetite was chemically treated with an active 3-(trimethoxysilyl)-1-propanethiol, to prepare TMSPT-FCMNPs with controlled morphology, stability, and low spin-orbit quantum properties. It was characterized using hyphenated FESEM- AFM, FTIR, XRD, AAS for successful adsorption of anionic Congo red (CR) dye, from real wastewater samples with high recoveries at different conditions. The low spin gives rise to enhanced pseudo 2nd order kinetics so that capacities reached 228.78 (mg g− 1 ) under Freundlich isothermal conditions with spontaneous and enthalpy directed thermodynamics. QSDFT, DFT and NLDFT, proved that the average Cassie approximation contact angle for CR/TMSPT-FCMNP is about 96.228o , which agrees with the requirements for spin orbit QM and low spin calculations. HSE06 calculations showed that FCMNPs have a cubic nominal inverse spinel structure with bulk Fe3+ Tet(S = − 5 /2) configuration, and equal distribution of Fe2+ Oct(S = 2) and Fe3+ Oct(S = 5 /2). Spin reordering could be obtained so that Fe3+ Oct− Tet has d5 (t 5 2g − eg 0) low spin configuration, while the Fe2+ Oct has d6 (t 6 2g − eg 0) low spin configuration and Fe2+ Tet has d6 (t 4 2g − eg 2) high spin configuration at the optimized molar ratio (0.5) with MExperimental net = +3.97μB per formula unit is obtained. NBO studies augmented the CR/ TMSPT-FCMNPs system stability as described by the energy gaps between HOMO and LUMO orbitals. The 4 binding affinity components ΔGelectrostatic , ΔGvan der Waals , ΔGpolar , and ΔGSASA were typically -47.308, -2.765, 28.546, -7.17 kJ/mol.

This paper underlined how the naturally occurring amygdalin (Amy) and raffinose (Raf) can inhibit the corrosion of aluminum in 0.1 M sodium hydroxide utilizing various tools at fixed temperatures. The obtained outcomes designated that the rate of corrosion of Al was set to rise with the rising alkali. The evaluated greater values of inhibition efficiencies (%IEs) of Amy and Raf (reaching 89% and 92%, respectively, at doses of 500 ppm) indicated that such compounds were efficient inhibitors against aluminum corrosion. Such %IE values depended on the concentrations and the structures of the inhibitors. The examined compounds played as mixed-kind inhibitors with a trivial cathodic priority. At similar concentrations, the average %IE values of raffinose were discovered to be faintly greater than those of amygdalin. The %IE values were reduced with the rising temperature. The acquired high values of %IEs were understood to be a result of the effective adsorption of the molecules of the examined compounds on the aluminum surface and the construction of a defensive film, and this adsorption was in agreement with the Langmuir adsorption isotherm. The thermodynamic and kinetic parameters were evaluated and debated. The kinetics of inhibition by the tested compounds were also investigated. The mechanisms of Al corrosion and its inhibition were discussed. The results acquired from the three utilized tools with respect to the values of %IEs were set to be in a good agreement with each other, confirming the validity of the obtained results of the existing study. Computational studies for the interactions between Amy and Raf molecules at the Al (1 1 1) surface were found to be consistent with the experimental results. The quadratic model of response surface methodology (RSM) modeling was used to expertly evaluate the relationships between the input parameters and the expected response (output)

The imine compounds (Z)-N-(2-(1-methyl-1H-pyrrol-2-yl)ethyl)-1-(thiophen-2-yl)ethan-1-imine (PSI) and (Z)-N-(2-(1-methyl-1H-pyrrol-2-yl)ethyl)-1-(pyridin-2-yl)ethan-1-imine (PPI) were effectively synthesized and described as corrosion inhibitors. The inhibition efficacy of PSI and PPI at carbon steel (CS) in formation water media was assessed using potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS) techniques, and quantum chemical calculations. PSI and PPI's inhibitory efficiency is related to the test's concentration. The maximum inhibitory efficiency was found in the presence of 1 × 10–3 M PSI and PPI, with 83 and 90 %, respectively. The two compounds are good mixed-type corrosion inhibitors, according to potentiodynamic polarization experiments. Both inhibitors' adsorption on CS surfaces followed the Langmuir adsorption isotherm, with both physisorption and chemisorption. Additionally, DFT studies and molecular dynamic (MD) simulation were used to explore the impact of PSI and PPI molecular on inhibition performance in formation water

Certain expired drugs could be used as proficient inhibitors for the corrosion of metals which have both economic and ecological profits. Thus, two selected expired drugs, namely, Ticarcillin and Carbenicillin were tested to inhibit the corrosion of aluminum in 1.0 M HCl solution. The techniques used in this paper were weight-loss (WL), potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The results illuminated that the inhibition efficiencies (% IEs) of the examined expired drug were increased as the drugs’ concentrations increased, while reduced with rising the corrosive solution concentration and temperature. The acquired higher % IEs were declined on the basis of strong adsorption of the drugs’ molecules on the aluminum surface and developing protective layer(s) and such adsorption was obeyed Langmuir isotherm. Both thermodynamic and kinetic parameters were determined that confirmed that the nature of adsorption was physical. The kinetics of aluminum corrosion and its inhibition by the employed drugs were studied that confirm the acquired higher % IEs. The examined drugs were set to act as mixed-kind inhibitors with slight anodic predominance. Results obtained from all used techniques revealed that the % IE of Ticarcillin was found to faintly greater than that of Carbenicillin and such used tools were agreed with each others. Finally, the mechanisms of aluminum corrosion in HCl and its inhibition were explained.