Document Type : Regular Article
Department of Chemistry, College of Science, Al-Nahrain University, Baghdad, Iraq
In this work, a new synthesized imidazole derivative, namely (N,N'E,N,N'E)-N,N'-(thiophene-2,5-diylbis(methanylylidene))bis(1H-benzo[d]imidazol-2-amine) which is donated as (SJ1), was tested as inhibitor in controlling the corrosion of carbon steel in 0.1 M hydrochloric acid solution by using open circuit potential (OCP), potentiodynamic polarization (PDP), at four different temperatures (293, 303, 313 and 323 K) and various of SJ1 concentrations. Furthermore, the surface morphology was investigated using both the Atomic force microscopy (AFM) and Scanning Electron Microscope (SEM), respectively. SJ1 was synthesized and characterized via using the Uv-vis, mass spectroscopy, 1H-NMR and 13C-NMR spectroscopy, and the element analysis CHN. From the experimental results shown that SJ1 can consider as an excellent corrosion inhibitor for carbon steel in acidic solution. The inhibition efficiency is increased with increasing the inhibitor concentration but is decreased with the increases of temperature, and the optimum inhibition efficiency by 5x10-4M of SJ1 is 96%. The adsorption behavior of the a new synthesized inhibitor on to the surface of the carbon steel was investigated and found is obeyed the Langmuir adsorption isotherm. DFT results were employed to study the electronic properties of SJ1.