Studies on the Influence of Temperature on the Adsorption of Some Cationic Surfactants on to Steel

• Main Authors: H.A. Al-Lohedan, E. Khamis, Z.A. Issa
• Format: Article
• Language: English
• Published: Hindawi - SAGE Publishing 1996-06-01
• Series: Adsorption Science & Technology
• Online Access: https://doi.org/10.1177/026361749601300301

The inhibition of steel corrosion by cationic surfactants has been investigated in acidic media. The study demonstrates a correlation between the inhibition action towards corrosion and increasing numbers of methylene groups per surfactant molecule. The mode of adsorption of inhibitor molecules on the steel surface in H 2 SO 4 solutions containing different concentrations of cetyltrimethylammonium bromide (CTABr), n-tetradecyl- N,N,N -trimethylammonium bromide (TDTABr), n-dodecyl-trimethylammonium bromide (DDTABr) and n-decyltrimethylammonium bromide (DTABr) has been investigated. Measurements have been conducted at temperatures ranging from 10°C to 50°C for all surfactants studied. The activation parameters E a and ΔS, and the thermodynamic parameters ΔG 0 ads. , ΔH 0 ads. and ΔS 0 ads. , have been determined and their values discussed. The Temkin adsorption isotherm and a recent kinetic–thermodynamic model fit the process of surfactant adsorption on to a steel surface well. The binding constant, the free energy of adsorption, the lateral interaction and the number of active sites are reported.