Electrochemical and Morphological Study of Steel in 1 M HCl in the Presence of Task Specific Liquid

In the present study, corrosion inhibition influence of novel cationic surfactant (CS) with imidazole structure (1-methyl-3-octadecane imidazolium hydrogen sulfate) on low carbon steel in 1 M HCl was investigated by implementing weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques. Increasing the amount of surfactant adequately leads to an increment of the inhibition efficiency of novel CS. According to the obtained results from EIS measurements, inhibition efficiency was about 34% in the presence of 1 ppm surfactant, increasing to about 96.8% at the 25 ppm (near critical micelle concentration) surfactant concentration. Also the effects of temperature and the synergistic effect between surfactant and NaHSO4 salt were studied. The inhibition efficiency increased with the increase of NaHSO4 concentration and reached the maximum value near 0.1 M and experienced a plummet in the temperature range of 30-50 °C. Potentiodynamic polarization measurements revealed that the surfactant acts as mixed-type inhibitors. Results obtained from weight loss, polarization, and impedance measurements are in proper agreement and confirmed the fact that this surfactant is an excellent inhibitor for low carbon steel in 1 M HCl environment. The surface morphology of inhibited and uninhibited metal samples was investigated by atomic force microscope (AFM) and field emission scanning electron microscope (FE-SEM).