Investigating the Anticorrosion Potentials of Expired Nevirapine Antiretroviral as Inhibitor of Potential Crude Oil Steel in Acidic Medium

The anticorrosion potential of expired nevirapine antiretroviral drug was investigated using both chemical (gravimetric and thermometric) and electrochemical (electrochemical impedance spectroscopy and potentio dynamic polarization) techniques. In both methods of measurements, the nevirapine inhibitor acted as an excellent inhibitor (98.9% inhibition efficiency). The inhibitor was good at all the tested temperatures but with best active performance at lower temperatures (98.1 %, 89.8 % and 84.6 % at 313 K, 323 K and 333 respectively), which explains a physical adsorption process. There was decreasing corrosion rate as inhibitor concentration was increased indicating that the nevirapine significantly halted the 0.5 M HCL acid reaction on the steel. The analysis showed that the charge transfer resistance values increased while the double layer capacitance values decreased with increasing nevirapine concentration which by this confirmed the earlier results from chemical techniques commending the excellent performance of the inhibitor. Langmuir adsorption showed good correlation and a monolayer adsorption process while the absorption free energy described the inhibitor as being stable and spontaneous.