Corrosion Protection of Mild Steel in Hydrochloric Acid at 308 K using Benzimidazole Derivatives: Weight Loss, Adsorption and Quantum Chemical Studies

For the first time, the investigation and characterization of Benzimidazole derivatives, as a potential corrosion inhibitors for mild steel in acidic aqueous solutions has been reported. The inhibition efficiency was calculated based on the data using weight loss, surface studies and basic computational calculations. The values reported in this manuscript were 80% for P1 and 89 for P2. The adsorption of the inhibitors on the mild steel surface was found to obey the Langmuir’s adsorption isotherm. The results obtained from chemical and theoretical techniques are in good agreement with each other

Imidazo[4,5-b]pyridines as a New Class of Corrosion Inhibitors for Mild Steel: Experimental and DFT Approach

6-Bromo-2-methyl-1H-imidazo[4,5-b]pyridine (P1), was investigated for its adsorption and corrosion inhibition traits for mild steel corrosion in 1.0 M HCl solution. Gravimetric, potentiodynamic polarization and electrochemical impedance spectroscopy methods, were used to test the nature of adsorption and the inhibition effect of P1 on the mild steel in acidic media. It was found that the inhibition efficiency improved with the increase of P1 concentration in the acid solution (1.0 M HCl). The adsorption of P1 favored Langmuir adsorption isotherm. The results of corrosion tests confirmed that P1 could serve as an efficient corrosion inhibitor for the mild steel in 1.0 M HCl solution, yielding a high efficiency and low risk of environmental pollution. The theoretical quantum chemical calculations were in good correlation with the experimental result

Superconductivity in the YIr2Si2 and LaIr2Si2 Polymorphs

We report on existence of superconductivity in YIr2Si2 and LaIr2Si2 compounds in relation to crystal structure. The two compounds crystallize in two structural polymorphs, both tetragonal. The high temperature polymorph (HTP) adopts the CaBe2Ge2-structure type (space group P4/nmm) while the low temperature polymorph (LTP) is of the ThCr2Si2 type (I4/mmm). By studying polycrystals prepared by arc melting we have observed that the rapidly cooled samples retain the HTP even at room temperature (RT) and below. Annealing such samples at 900C followed by slow cooling to RT provides the LTP. Both, the HTP and LTP were subsequently studied with respect to magnetism and superconductivity by electrical resistivity, magnetization, AC susceptibility and specific heat measurements. The HTP and LTP of both compounds respectively, behave as Pauli paramagnets. Superconductivity has been found exclusively in the HTP of both compounds below Tsc (= 2.52 K in YIr2Si2 and 1.24 K in LaIr2Si2). The relations of magnetism and superconductivity with the electronic and crystal structure are discussed with comparing experimental data with the results of first principles electronic structure calculations