Influence of Hydroxyl Groups on the Inhibitive Corrosion of Gemini Surfactant for Carbon Steel.

The corrosion inhibition performance of propanediyl-1,3-bis(,-dimethyl-dodecylammonium bromide) and propanediyl-1,3-bis(,-dihydroxyethyl--dodecylammonium bromide), abbreviated as PDDB and PDHDB, respectively, for carbon steel in 1.0 mol·L hydrochloric acid solution was investigated using the gravimetric method and various electrochemical techniques, together with scanning electron microscopy and energy-dispersive spectrometry. Results show that PDHDB always has a better inhibition performance relative to PDDB, which can be attributed to the introduction of hydroxyl groups at the hydrophilic headgroups, thereby causing an extra interaction between inhibitors and the metal surface and favoring its adsorption. These findings highlight that the modification to the headgroups of Gemini-type inhibitors may be another effective approach to improving their inhibition performance.