Investigating the synergism of some hydrazinecarboxamides and iodide ions as corrosion inhibitor formulations for mild steel in hydrochloric Acid: Experimental and computational studies

Comprehensive Investigation of the Adsorption, Corrosion Inhibitory Properties, and Quantum Calculations for 2-(2,4,5-Trimethoxybenzylidene) Hydrazine Carbothioamide in Mitigating Corrosion of XC38 Carbon Steel under HCl Environment

This study investigates the inhibitory effects of 2-(2,4,5-trimethoxy benzylidene) hydrazine carbothioamide (TMBHCA) on the corrosion of carbon steel in a 1 M HCl solution across various concentrations. The assessment employs a comprehensive approach, combining gravimetric analysis, potentiodynamic polarization tests, and electrochemical impedance spectroscopy (EIS). Additionally, scanning electron microscopy (SEM) and quantum chemical calculations are employed to provide a thorough understanding of the corrosion inhibition mechanism. The influence of exposure time on mild steel corrosion is systematically examined. Results reveal a remarkable reduction in the corrosion rate of steel, with TMBHCA demonstrating its highest inhibition efficiency of 97.8% at 200 ppm. Potentiodynamic polarization studies characterize TMBHCA as a mixed-type inhibitor, while Nyquist plots illustrate increased charge transfer resistance and decreased double-layer capacitance with escalating TMBHCA concentrations. Consistency between weight loss measurements and electrochemical findings further validates the efficacy of TMBHCA as a corrosion inhibitor. SEM images substantiate and visually support the obtained results. An immersion test conducted at 25 °C over 28 days showcases a notable enhancement in TMBHCA efficiency (IE%) from 45.16% to 92.43% at 200 ppm as the immersion period progresses from 1 day to 28 days. This improvement is attributed to the augmented adsorption of inhibitor molecules on the steel surface over time. These comprehensive findings significantly contribute to our understanding of TMBHCA's corrosion inhibition behavior, emphasizing its potential as a highly efficient corrosion inhibitor for diverse industrial applications.

Effect of Adsorption and Interactions of New Triazole-Thione-Schiff Bases on the Corrosion Rate of Carbon Steel in 1 M HCl Solution: Theoretical and Experimental Evaluation

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-methyl-2,4-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.

Expired Antifungal Drugs as Effective Corrosion Inhibitors for Carbon Steel in 1 M HCl Solution: Practical and Theoretical Approaches

The anticorrosion potency of two expired antifungal drugs, namely, bifonazole (BIF) and terconazole (TER), for X65 carbon steel (X65CS) in a 1.0 M HCl solution was estimated using practical and computational measurements. The results of all methods applied showed that the percentage of anticorrosive efficacy (% AE) increased for expired BIF and TER and reduced at elevated temperatures. The % AE values of expired BIF and TER (375 mg L-1) reached 92.08 and 94.19%, respectively, using polarization methods. The anticorrosion activities of the two expired drugs were interpreted based on their adsorption on the X65CS surface. The adsorption occurred according to the Langmuir isotherm model. The polarization results indicated that the expired drugs BIF and TER were mixed inhibitors. The impedance results showed a single capacitive loop, confirming that the charge transfer process controlled the corrosion of X65CS. Expired BIF and TER served as good pitting inhibitors by shifting the pitting potential to positive values. The thermodynamic functions of activation and adsorption were defined and explained. Density functional theory and Monte Carlo simulations were used to investigate the BIF and TER inhibitors. The theoretical parameters were consistent with the experimental results. The anticorrosion efficiencies determined using the various methods were in complete agreement.

Corrosion inhibition relevance of semicarbazides: electronic structure, reactivity and coordination chemistry

Semicarbazide (OC(NH2)(N2H3)) and thiosemicarbazide (SC(NH2)(N2H3)) are well-known for their coordination complex formation ability. They contain nonbonding electrons in the form of heteroatoms (N, O and S) and π-electrons in the form of >C=O and >C=S through they strongly coordinate with the metal atoms and ions. Because of their association with this property, the Semicarbazide (SC), thiosemicarbazide (TSC) and their derivatives are widely used for different applications. They serve as building blocks for synthesis of various industrially and biologically useful chemicals. The SC, TSC and they derivatives are also serve as strong aqueous phase corrosion inhibitors. In the present reports, the coordination ability and corrosion protection tendency of Semicarbazide (SC), thiosemicarbazide (TSC) and their derivatives is surveyed and described. These compounds are widely used as inhibitors for different metals and alloys. Through their electron rich sites they adsorb on the metal surface and build corrosion protective film. Their adsorption mostly followed the Langmuir adsorption isotherm. Through their adsorption they increase the value of charge transfer resistance and decrease the value of corrosion current density. Computational studies adopted in the literature indicate that SC, TSC and their derivatives adsorb flatly and spontaneously using charge transfer mechanism.

Environmental Remediation through Catalytic Inhibition of Steel Corrosion by Schiff’s Bases: Electrochemical and Biological Aspects

The environmental impact of corrosion is very dangerous and consumes much of world’s efforts and funds. This work discusses the safeguarding of the environment, metals, and metal-infra structures by efficient Schiff’s base inhibitors. The corrosion inhibitors [(1E,3E)-N1,N3-dibutyl-1-(thiophen-2-yl)butane-1,3-diimine] (GSB-I) and [(1Z,3Z)-N1,N3-bis(4-methylhexan-2-yl)-1-(thiophen-2-yl)butane-1,3-diimine] (GSB-II) were successfully synthesized and evaluated for the protection of API 5L X65 steel (CS) in 1 M HCl media using electrochemical techniques, SEM/EDS, and quantum chemical calculations. GSB-I and GSB-inhibitory I’s efficiency is proportional to the concentration of the test. In the presence of 1 mM GSB-I and GSB-II, the maximum inhibitory efficiency was determined to be 90.6 and 93.8 percent, respectively. According to potentiodynamic polarization tests, the two compounds are effective inhibitors of mixed-type corrosion. The physisorption and chemisorption of both inhibitors followed the Langmuir adsorption isotherm on CS surfaces. The biological reactivity of both GSB has been examined, and encouraging results have been obtained as antifungal, antibacterial, and biocidal agents against sulfate-reducing bacteria (SRB). In addition, using DFT calculations and molecular dynamic (MD) simulation, the effect of GSB-I and GSB-II molecular configuration on corrosion inhibition behavior in acidic environments was investigated.