Newly synthesized quaternary ammonium mono-cationic and di-cationic surfactants utilized for carbon steel corrosion inhibition during acidization process of oil and gas wells.

Both chemical and electrochemical techniques were employed to evaluate the corrosion inhibition performance of two newly synthesized mono-cationic and di-cationic surfactants toward carbon steel (CS) corrosion in 1 M hydrochloric acid solution. The investigated compounds included a mono-cationic surfactant [BDDA-Cl], namely (E)-N-(2-(2-(benzylideneamino)ethoxy)-2-oxoethyl)-N,N-dimethyldodecan-1-aminium chloride, and a di-cationic surfactant [DDPDA-Cl2], namely (6E,8E)-N1,N14-didodecyl-N1,N1,N14,N14-tetramethyl-2,13-dioxo-7,8-diphenyl-3,12-dioxa-6,9-diazatetradeca-6,8-diene-1,14-diaminium chloride. The results revealed that both synthesized surfactants exhibited remarkable corrosion inhibition performance through efficient adsorption onto the carbon steel surface. Among the investigated compounds, DDPDA-Cl2 demonstrated superior inhibition efficiency, reaching 95.16%, compared with 91.73% for BDDA-Cl at a concentration of 1 × 10-3 M at 25 °C. The enhanced inhibition performance of the di-cationic surfactant was attributed to its stronger adsorption affinity and greater surface coverage. The outstanding corrosion protection performance was associated with synergistic adsorption involving both chemisorption and physisorption mechanisms, resulting in the formation of a compact protective layer that effectively suppressed the corrosion process.