A comparative study on the electrochemical behavior of mild steel in sulfamic acid solution in the presence of monomeric and gemini surfactants
Artikel i vetenskaplig tidskrift, 2011

The electrochemical behavior of mild steel in sulfamic acid solution in the presence of a gemini cationic surfcatant, butanediyl-1,4- bis(dodecyldimethylammonium bromide (12-4-12), and its monomeric counterpart, dodecyltrimethylammonium bromide (DTAB), was investigated as a function of the surfactant concentration by means of electrochemical impedance spectroscopy (EIS). The critical micelle concentration (cmc) values of DTAB and 12-4-12 in 1 M sulfamic acid solution, measured by surface tension measurement, were found to be 1.2 and 0.02 mM, respectively. The EIS results revealed a higher charge transfer resistance in 12-4-12 solution compared to that in DTAB solution at the same concentration normalized by the cmc (c/cmc). The morphology of the steel samples after being exposed to the acidic test solutions was examined by atomic force microscopy (AFM). The AFM micrographs showed a reduction of surface roughness in the presence of the surfactant which is more evident at higher surfactant concentrations. The adsorption of both surfactants in the sulfamic acid solution was studied by Langmuir and Flory-Huggins adsorption isotherms at submicellar concentrations.

Mild steel

Cationic surfactants

EIS

Sulfamic acid

Adsorption

Författare

M. Motamedi

Institute for Color Science and Technology

Ali Tehrani

Chalmers, Kemi- och bioteknik, Teknisk ytkemi

M. Mahdavian

Sahand University of Technology

Institute for Color Science and Technology

Electrochimica Acta

0013-4686 (ISSN)

Vol. 58 1 488-496

Ämneskategorier

Kemi

DOI

10.1016/j.electacta.2011.09.079