Benzodiazepine Derivatives as Corrosion Inhibitors of Carbon Steel in HCl Media: Electrochemical and Theoretical Studies

Protection of Metals and Physical Chemistry of Surfaces - New benzodiazepine derivatives, namely 8-Chloro-1,2,3,4,10,11-hyxahydrospiro[cyclohexane-1,11-dibenzo[1,4]diazipine] and...     

N-benzyl-N,N-bis[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]amine as corrosion inhibitor of steel in 1 M HCl

The inhibition effect of a new bipyrazole derivative namely N-benzyl-N,N-bis[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]amine (BBPA) on the corrosion of steel in 1 M HCl is studied at 308 K. Weight-loss measurements, potentiodynamic polarisation, linear polarisation and impedance spectroscopy (EIS) methods were used. Results show that BBPA is a good inhibitor and inhibition efficiency reaches 87% at 5 · 10^− 4 M. The values of the inhibition efficiency calculated from these techniques are reasonably in good agreement. Polarisation curves revealed that this organic compound acts as a mixed-type inhibitor. The temperature effect on the corrosion behaviour of steel in 1 M HCl with and without BBPA at 5 · 10^− 4 M is studied in the temperature range 308-353 K. The associated activation energy is determined. The adsorption of BBPA on the steel surface obeys to the Langmuir's adsorption isotherm. EIS measurements show that the transfer resistance increases with the inhibitor concentration. Efficiency is explained by the theoretical studies.     

Theoretical Prediction and Experimental Study of Benzimidazole Derivate as a Novel Corrosion Inhibitor for Carbon Steel in 1.0 M HCl

Protection of Metals and Physical Chemistry of Surfaces - The inhibiting effect of benzimidazole derivate (DBI) on corrosion of carbon steel (CS) at temperature range of 303–333 K was...     

Corrosion inhibition performance of 4-(prop-2-ynyl)- [1,4]-benzothiazin-3-one against mild steel in 1 M HCl solution: Experimental and theoretical studies

4-(prop-2-ynyl)-2H [1,4]-benzothiazin-3(4H)-one (PBO) was synthesized and evaluated on corrosion resistance for mild steel (MS) in1 M HCl environment. The molecular and crystal structure of PBO has been determined by single-crystal X-ray crystallography, Hirshfeld surface (HS) analysis was carried out by using Crystal Explorer 17.5. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques were used to find corrosion rate (CR) and corrosion inhibition efficiency (η) in the presence and absence of PBO. These techniques were supported with energy dispersive X-ray (EDX) and scanning electron microscope (SEM). Molecular Dynamics Simulation (MDS) and Frontier Molecular Orbital (FMO) are realized by means of the Density Functional Theory (DFT) method. The results show that PBO could offer an inhibition efficiency of 92% at 303 K. The type of inhibition mechanism of PBO was mixed-type. The Langmuir isotherm proved the highest compliance with experimental data, representing the generation of protective mono-layer of inhibitors on the MS substrate. The SEM pictures displayed a metallic substrate covered with a highly compact protective layer covered. The theoretical findings suggested by electronic/atomic computer simulations supported the inhibitive chemicals interfacial adsorption through reactive centres.