The Study Of Metal Corrosion Resistance Based On Organic Ionic Liquid Molecular Assembly

With the rapidly development of industrialization,there have been huge economic losses caused by the corrosion of metal materials every year in China.Therefore,it has become one of the main researches in corrosion field to develop new types of organic corrosion inhibitors with high efficiency,environmental protection and low toxicity in recent years.This thesis designed and synthesized a series of organic ionic liquid corrosion inhibitors C1-C6 containing monoimidazole rings and diimidazole rings.The target compound has good solubility in sulfuric acid medium,and also the nitrogen heterocycle in its molecular structre can complex ion on the surface of copper metal,forming an organic protective film on the copper surface to isolate the metal from direct contact with sulfuric acid corrosive medium.In this paper,the effect of the chemical structure of the target molecule on the corrosion inhibition of copper in 0.5 m sulfuric acid solution was investigated,and the corrosion resistance mechanism was further studied.Observing the corrosion inhibitors aggregates' changes in size and morphology in sulfuric acid aqueous solution with aggregation time and aggregation concentration by scanning electron microscopy(SEM),transmission electron microscopy(TEM)and dynamic light scattering(DLS).The results show that when the concentration of inhibitor C1-C6 is 0.050 m M and the aggregation time is 8 h,the morphology and size of aggregates no longer change significantly with concentration and time,which means the inhibitor molecules reach the self aggregation stable.We tested the inhibitory effect of the corrosion inhibitors C1-C6 in 0.5 M sulphuric acid solution for copper by using electrochemical impedance spectroscopy(EIS),potentiodynamic polarization curve(Tafel),scanning electron microscopy(SEM)on copper surface,adsorption isotherm line and futher revealed the corrosion inhibition mechanism of corrosion inhibitors on copper surface by fourier transform infrared spectrometer(FT-IR),attenuated total reflectance infrared spectroscopy(ATR-IR)?X-ray photoelectron spectroscopy(XPS),atomic force microscope(AFM).The experimental results showed that the inhibitors C1-C6 of lower concentration has high corrosion inhibition efficiency for copper.The optimum inhibitor concentration is 0.050 m M,and the corrosion inhibition performance follows C6>C5>C4>C3>C2>C1.It indicated that with the increase of the number of adsorption centers and the increase of the fatty carbon chain,the inhibition efficiency of the target molecule aggregates increases and meanwhile the corrosion inhibitors' significant protection for copper from corrosion is by forming a dense protective film on copper surface via chemisorption...