金竹叶提取物的缓蚀性能研究

Study on Corrosion Inhibition Performance of Phyllostachys sulphurea Leaves Extract

用失重法、动电位极化曲线、电化学阻抗谱(EIS)和原子力显微镜(AFM)研究了20℃时天然植物金竹叶提取物(PSLE)在1.0 mol/L HCl溶液中对冷轧钢的缓蚀作用,并用吸附观点探讨了缓蚀作用机理。结果表明:PSLE对冷轧钢具有良好的缓蚀作用,质量浓度为100 mg/L时缓蚀率高达94.2%。PSLE通过含O、N的极性官能团,在钢表面发生吸附起到缓蚀作用,且吸附规律符合Langmuir吸附等温式。极化曲线表明,PSLE为混合抑制型缓蚀剂;其EIS谱呈半圆容抗弧,电荷转移电阻随缓蚀剂质量浓度(c)的增加而增大。AFM表明PSLE在钢表面吸附形成了致密的缓蚀剂膜层。

The main functional groups of Phyllostachys sulphurea（Carr.）Riviere leaves extract（PSLE） were characterized by Fourier transform infrared（FT-IR） spectroscopy.The inhibition effect of PSLE on the cold-rolled steel（CRS） in 1.0mol/L HCl solution at 20℃ was studied by methods of weight loss,potentiodynamic polarization curves,electrochemical impedance spectroscopy（EIS）and atomic force microscopy（AFM）.Meanwhile,the inhibitive mechanism was proposed from the adsorption viewpoint.The results show that PSLE is a good corrosion inhibitor,and maximum inhibition efficiency is up to 94.2% at concentration 100mg/L.PSLE exhibits its inhibitive performance via adsorption of functional groups containing N and O atoms on steel surface,and the adsorption of PSLE on CRS surface obeys Langmuir adsorption isotherm.Polarization curves reveal that PSLE behaves as a mixed-type corrosion inhibitor.EIS spectra exhibit one capacitive loop and charge transfer resistance value increases with the increase of inhibitor mass concentration（c）.AFM results reveal that PSLE can be adsorbed on steel surface to form a dense protective film.