混凝土模拟液中咪唑啉衍生物与四乙烯五胺间缓蚀协同效应

Synergistic Effect of Inhibitors of an Imidazoline Derivative and Tetraethylenepentamine on Corrosion Inhibition of Steel Rebar in an Artifial Concrete Pore Solution

在含3.5%Na Cl饱和Ca(OH)2溶液中,利用线性极化、动电位扫描和电化学阻抗技术,研究了一种咪唑啉衍生物,即1-(N N′-2-羟基乙撑醚-氨乙基)-2-硬植酸咪唑啉(HASI)与四乙烯五胺(TEPA)复配缓蚀剂对钢筋的缓蚀性能及二者间的缓蚀协同作用,通过分子动力学模拟对HASI,TEPA和不同比例复配物在Fe表面的吸附行为进行了探讨。结果表明:与空白溶液相比,添加缓蚀剂后钢筋腐蚀电流密度下降,耐Cl-侵蚀性能增强。随复配物中HASI含量的增加,缓蚀效率升高,钢筋自腐蚀电位负移,且钢筋电极钝化区间增大,表明复配化合物对碱性Cl-溶液中钢筋的腐蚀具有很好的抑制作用,HASI与TEPA间具有明显的缓蚀协同效应。动力学模拟结果表明,HASI与TEPA可同时在Fe表面发生吸附,并形成致密的吸附保护膜,有效阻碍溶液中侵蚀性物质与金属基体的接触,进而抑制钢筋的腐蚀。

Inhibition performance and synergistic effect of an imidazoline derivative, namely 1-[N, N- bis（hydroxylethylether）- aminoethyl]- 2- stearicimidazoline （HASI） with tetraethylenepentamine （TEPA） on the corrosion inhibition of steel rebar in an artificial concrete pore solution containing 3.5%NaC1 were investigated using linear polarization, potentialdynamic polarization and electroch- emical impedance spectroscopy （EIS） techniques, while molecular dynamics （MD） simulation was employed to explore the co-adsorption behavior of the composite inhibitors on the metallic iron sur- face. Results indicate that after the addition of inhibitors, the corrosion current density of steel re- bar was reduced and the corrosion resistance of steel rebar was enhanced. With increasing content of HASI in the composite inhibitors, the inhibition efficiency gradually increased, the corrosion po- tential shifted significantly to negative, and therewith a more positive pitting potential and a wide passive region were observed in comparison with that in the blank solution, which reveal that the chloride-induced corrosion on steel rebar was effectively retarded by the composite inhibitor, in oth- er words, HASI and TEPA exhibited a good synergistic effect on the corrosion inhibition of steel rebar in the artificial concrete pore solution. MD results show that molecules of HASI and TEPA could simultaneously be adsorbed on the metallic iron surface to form a more compact protective film and consequently became a barrier to hinder the access of aggressive species in the corrosive solution to the metal surface, thereby to effectively inhibit the corrosion of steel rebar.