Expired Drugs: Environmentally Safe Inhibitors for Aluminium Corrosion in 1 M H2SO4

Abstract

The corrosion inhibition of aluminium in 1 M H2SO4 using expired drugs of moxifloxacin and betnesol as corrosion inhibitors has studied by weight loss measurements, potentiodynamic polarization studies, electrochemical impedance spectroscopy and scanning electron microscope analysis. The experimental studies show that drugs thus used inhibitors reduce the corrosion of aluminium and the inhibition efficiency increases with addition of moxifloxacin and betnesol at various temperatures. Moreover, potentiodynamic polarization curves illustrate that both betnesol and moxifloxacin act as mixed type inhibitors but predominantly anodic process of corrosion. In addition, EIS studies show that transfer resistance increases with the addition of inhibitor concentration. The effect of temperature on aluminium corrosion upon with and without the presence of inhibitors was also investigated in detail. Thermodynamic and adsorption isotherm calculations reveal that the used drug molecules have both chemisorption and physisorption with aluminium metal and followed the Langmuir adsorption isotherm.