Effect of Tryptophan on the corrosion behavior of low alloy steel in sulfamic acid

Arabian Journal of Chemistry

Aliaa A.M. Hassan¹  Hesham T.M. Abdel-Fatah¹  S.M. Abd El Wahaab²  Salah A.M. Rashwan³ 

[1] Central Chemical Laboratories, Egyptian Electricity Holding Company, Sabtia, Cairo, Egypt;Chemistry Department, Faculty of Science, Ain Shams University, Abbassia, Cairo, Egypt;Chemistry Department, Faculty of Science, Sues Canal University, Ismailia, Egypt;

关键词: Corrosion inhibition;    Acid cleaning;    Sulfamic acid;    Amino acids;    EIS;    EFM;   

DOI  :  10.1016/j.arabjc.2011.11.012

来源: DOAJ

【 摘 要 】

Sulfamic acid is widely used in various industrial acid cleaning applications. In the present work, the inhibition effect of Tryptophan (Tryp) on the corrosion of low alloy steel in sulfamic acid solutions at four different temperatures was studied. The investigations involved electrochemical methods (electrochemical impedance spectroscopy; EIS and the new technique electrochemical frequency modulation; EFM) as well as gravimetric measurements. The inhibition efficiency and the apparent activation energy have been calculated in the presence and in the absence of Tryp. It is most probable that the inhibition property of Tryp was due to the electrostatic adsorption of the protonated form of Tryp on the steel surface. Adsorption of the inhibitor molecule, onto the steel surface followed the Temkin adsorption isotherm. The thermodynamic parameters of adsorption were determined and discussed. All of the obtained data from the three techniques were in close agreement, which confirmed that EFM technique can be used efficiently for monitoring the corrosion inhibition under the studied conditions.

【 授权许可】

Unknown