Corrosion of mild steel in hydrochloric acid solution in the presence of two cationic gemini surfactants with and without hydroxyl substituted spacers

The corrosion inhibition mechanism of mild steel in acidic solution and in the presence of two cationic gemini surfactants have been studied. These are two surfactants having 12-carbon hydrophobic tails: one with a tetramethylene spacer and the other one with the same spacer containing two hydroxyl groups. EIS and polarization and electrochemical noise measurements revealed superior corrosion inhibition of hydroxyl functional surfactant compared with its counterpart with no hydroxyl group. Surface analysis including AFM, and SEM confirmed less corrosion attacks on the sample exposed to hydroxyl functional surfactant solution. Quantum chemical parameters revealed a good correlation with electrochemical results.