盐酸介质中咪唑离子液体对铜的缓蚀作用

Corrosion Inhibitor of Imidazolium Ionic Liquid on Copper in HCl Solution

以1-甲基咪唑、1,4-丁烷磺内酯和浓硫酸为原料,用乙醚洗涤合成了1-甲基-3-(4-硫酸基丁基)咪唑硫酸盐(4-BMIM)缓蚀剂。采用动电位极化和交流阻抗技术研究了4-BMIM在5%HCl溶液中对铜的缓蚀性能及作用机理。实验结果表明:缓蚀效率随着缓蚀剂浓度的增加先增大后降低,当浓度为0.03mol/L时,缓蚀效率最高;同一浓度下,随着温度的升高缓蚀效率降低。动电位极化表明咪唑离子的加入对铜的阴、阳极腐蚀过程均有抑制作用,是混合型缓蚀剂。热力学计算结果表明咪唑离子液体吸附在铜表面,其吸附机制为自发进行的物理吸附,并且在铜/溶液界面的吸附遵循Langmuir吸附等温式。

1-methy-3-（4vsulfate butyl） imidazolium ionic liquid was synthetized using 1-methylimidazole, 1, 4- butane sultone, concentrated sulfuric acid by being washed with ether. The potentiodynamic polarization and electrochemical impedance spectroscopy were used to study the corrosion mechanism and inhibiting performance of 4- BMIM on copper in 5 % hydrochloric acid medium. The results show that the inhibition efficiency first increases and then decreases with the increase of inhibition concentration, and the maximum inhibition efficiency is obtained with 0.03mol/L 4-BMIM. However, the inhibition efficiency decreases with the increase of temperature at the same concentration. The polarization curves show that 4-BMIM is a mixed type inhibitor, and inhibits both the cathodic and anodic reactions. The results of thermodynamic calculation reveal that adsorption mechanism of 4- BMIM on the copper surface is spontaneous physisorption and it fits the Langmuir adsorption isotherm.