关键词: 十二烷基苯磺酸钠, 六亚甲基四胺, 失重法, 分子动力学模拟, 扩散系数

Abstract:

The synergistic inhibitive effect of sodium dodecylbenzene sulfonate (SDBS) and hexamethylene tetramine (HA) toward Q235 steel in hydrochloric acid was investigated by the static weight loss method. We also studied the inhibition mechanism by molecular dynamics simulations with regard to the inhibition of aggressive particle diffusion by inhibitor membranes. SDBS and HA were found to have individual inhibition efficiencies of 82.82% and 79.46%, respectively. These inhibition efficiencies increased to an efficiency of 92.78% when SDBS and HA were combined. Molecular dynamics simulations indicated that the free volume of the inhibitor membrane decreased significantly when SDBS and HA were used together compared with the case when they were used individually. Therefore, the self-diffusion of the inhibitor molecules becomes weaker and passive diffusion of the aggressive particles, which is caused by the mobility of the membrane, also decreases. The diffusion coefficient of the aggressive particles inside the inhibitor membrane shows that the diffusion of the aggressive particles is strongly hindered by the inhibitor membrane because of the synergistic effect between SDBS and HA and that the inhibition efficiency is enhanced.

Key words: Sodium dodecylbenzene sulfonate, Hexamethylene tetramine, Weight loss method, Molecular dynamics simulation, Diffusion coefficient