Corrosion Inhibition Efficiency on X65 Steel of Single Surfactant and Mixtures of Alkyl Benzyl Dimethyl Ammonium Chlorides

The corrosion inhibition on X65 steel of a series of single and mixtures of surfactants, alkyl benzyl dimethyl ammonium (CnBDMAC) chloride surfactants, was studied. The surfactant properties were studied by surface tension measurement, optical spectrometry, and Gaussian simulations/calculations. The surface tension was measured to determine critical micelle concentrations (CMC) and adsorption isotherms at the air-water surface. The corrosion inhibition efficiency was evaluated using electrochemical measurements under various conditions: different surfactant concentrations, hydrocarbon chain length, temperature, pH, and salinity. These electrochemical methods include linear polarization, electrochemical impedance spectroscopy (EIS), and Tafel slope method. Results are presented to show the inhibition effect dependence on the above mentioned factors. Mechanism behind corrosion inhibition was discussed.