Strengthened adsorption and corrosion inhibition of new single imidazole-type ionic liquid molecules to copper surface in sulfuric acid solution by molecular aggregation

Abstract

This study proposes to use molecular aggregation method of organic ionic liquid molecules (OILMs) to intensify adsorption and corrosion inhibition to copper surface in sulfuric acid solution. Three new single imidazole-type OILMs including long carbon chain were synthesized, which were characterized by different methods such as nuclear magnetic resonance (NMR) and elemental analysis. The results suggest that the OILMs could process regular molecular assembly in sulfuric acid solution. The formed OILMs aggregates have been shown dependence on the OILMs concentrations and aggregation time. The chemistry adsorption of the OILMs aggregates on copper surface was demonstrated by various means including attenuated total reflection infrared spectroscopy (ATR-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and spectroscopic ellipsometry and contacting angles, and atomic force microscopy (AFM) as well as scanning electron microscopy (SEM) imaging. Thus, the hydrophobic adsorption layers of the OILMs aggregates were yielded on copper surface. The electrochemistry survey suggests that the OILMs aggregates present nice corrosion resistance effect to copper in sulfuric acid solution (the maximal corrosion inhibition efficiency, >93%). The results were further understood by the theoretical simulation computation.