Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (01): 120-126.doi: 10.3866/PKU.WHXB20110117

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Inhibition Performance of an Imidazoline Derivative as a Gas-Liquid Two-Phase Inhibitor for Q235 Steel against CO2 Corrosion

WANG Bin, DU Min, ZHANG Jing   

  1. Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education,College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, Shandong Province, P. R. China
  • Received:2010-09-20 Revised:2010-10-30 Published:2010-12-31
  • Contact: DU Min
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (40806030).


We investigated the inhibition performance of a new imidazoline derivative inhibitor, TAI, which can be used as a gas-liquid two-phase inhibitor against CO2 corrosion by weight-loss method, electrochemical impedance spectroscopy (EIS), Fourier-transform infrared (FT-IR) spectroscopy, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). Results revealed that the thioureido imidazoline inhibitor was an effective inhibitor against CO2 corrosion in gas and liquid two phases. Surface analysis by AFM showed that damage to the metallic surface was considerably reduced in the presence of the TAI inhibitor. A bigger adhesive force between the AFM probe and the steel surface was detected owing to hydrophobic interaction from the inhibitors in the two phases. The long range-repulsive force between the AFM probe and the steel surface increased in gas phase but decreased in liquid phase by the screening effect of surface charges. XPS and FT-IR spectroscopy proved that the adsorption films on the metal surfaces with protective properties of TAI and acid hydrolysis products of the TAI (amides) were present in liquid phase and in gas phase, respectively. The above results further confirmed the hydrolysis mechanism of imidazoline derivatives in acid solution.

Key words: CO2 corrosion, Imidazoline derivative, Acid hydrolysis, Fourier transform infrared spectroscopy, Atomic force microscopy, X-ray photoelectron spectroscopy


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