稀土Ce^(4+)和香兰素在H_3PO_4介质中对钢的缓蚀协同效应

Synergistic Inhibition Effect of Rare Earth Ce^(4+) and Vanillin on Corrosion of Cold Rolled Steel in H_3PO_4 Media

采用失重法、电化学法和紫外-可见吸收光谱研究了3.0mol/LH3PO4介质中,稀土Ce4+和香兰素(4-羟基-3-甲氧基-苯甲醛)对冷轧钢的缓蚀协同效应。结果表明,香兰素对冷轧钢有中等程度的缓蚀作用,缓蚀率随其浓度的增加而增大,最大缓蚀率为66%,在钢表面的吸附符合Freundlich吸附模型;稀土Ce4+对冷轧钢的缓蚀作用较差,最大缓蚀率仅为20%左右。稀土Ce4+和香兰素复配后对冷轧钢产生了明显的缓蚀协同效应,最大缓蚀率可达90%。稀土Ce4+和香兰素在H3PO4介质中复配后形成了新的配合物,为混合抑制型缓蚀剂。

The synergistic inhibition effect of rare earth Ce4＋ and vanillin （ 4-hydroxy-3-methoxy-benzaldehyde） on the corrosion of cold rolled steel（ CRS） in 3. 0 mol/L H3PO4 solution was studied by mass loss,potentiodynamic polarization and UV-Vis spectrophotometry（ UV-Vis）. The present study reveals that vanillin exhibits a moderate inhibitive effect on the corrosion of CRS. The inhibition efficiency（ IE） increases with the concentration increase,and the maximum IE is 66%. The adsorption of vanillin on the CRS surface obeys Freundlich adsorption isotherm equation. Ce4 ＋ shows a poor inhibition performance and the maximum IE is not more than 20%. However,incorporation of rare earth Ce4 ＋ with vanillin significantly improves the inhibition performance and produces a synergistic inhibition effect. The maximum IE is as high as 90%. Ce4 ＋ and vanillin form a new complex,which acts as a mixed-type inhibitor.