Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (11): 3041-3046.doi: 10.3866/PKU.WHXB20101020

• QUANTUM CHEMISTRY AND COMPUTATION CHEMISTRY • Previous Articles     Next Articles

Molecular Dynamics Simulation of Corrosive Medium Diffusion in Corrosion Inhibitor Membrane

QIAO Gui-Min, REN Zhen-Jia, ZHANG Jun, HU Song-Qing, YAN You-Guo, TI Yang   

  1. College of Physics Science and Technology, China University of Petroleum, Dongying 257061, Shandong Province, P. R. China
  • Received:2010-05-06 Revised:2010-07-26 Published:2010-10-29
  • Contact: ZHANG Jun E-mail:dynamic_zh@163.com
  • Supported by:

    The project was supported by the China National PetroleumCorporation Innovation Foundation (07E1021, 2008D-5006-02) and Natural Science Foundation of Shandong Province, China (Y2006B35).

Abstract:

The corrosion inhibition mechanism of four 1-R1-2-undecyl-imidazoline inhibitors (R1: CH2COOH (A), CH2CH2OH (B), CH2CH2NH2 (C), H (D)) for carbon steel against carbon dioxide corrosion was investigated by molecular dynamics simulation, from the aspect of corrosive medium particle (H2O, H3O+, and HCO-3) diffusion to the metal surface hindered by the corrosion inhibitor membrane. The corrosion inhibition performance of these compounds was also evaluated by the theoretical method. The diffusion coefficients in various corrosion inhibitor membranes, the interaction energies between particles and membranes, and the self-diffusion performance of the membranes indicated that the four imidazoline inhibitors could form stable membranes, which could effectively limited the diffusion of corrosive medium particles to the metal surface, in order to inhibit or delay corrosion. With an increase in the polarity of the hydrophilic chain (R1), the ability of the membrane to hinder particle diffusion enhanced. The membrane was better at limiting the diffusion of charged particles (H3O+ and HCO-3) than that of a neutral particle (H2O). Based on the above analysis, we found that theoretically the corrosion inhibition performance of the four imidazoline inhibitors decreased as follows: A>B>C>D, which agrees with previous experimental results.

 

Key words: Molecular dynamics simulation, Corrosion inhibitor membrane, Corrosive medium, Diffusion coefficient

MSC2000: 

  • O641