Nano to micro self-aggregates of new bisimidazole-based copoly(ionic liquid)s for protecting copper in aqueous sulfuric acid solution

This study presents the synthesis of two new bisimidazole-based copoly(ionic liquid)s (PILs) through multi-step preparation routes. It is shown that the target PILs can display orderly molecular stacking, and nano to micro self-aggregates are yielded in aqueous sulfuric acid solution, which are characterized by various technologies including the scanning electron microscopy (SEM), the transmission electron microscopy (TEM) and the dynamic light scattering (DLS). The studied PILs aggregates show strong chemical adsorption onto the copper surfaces demonstrated by the Fourier transform infrared spectroscopy (FT-IR), the Raman spectroscopy as well as the X-ray photoelectron spectroscopy (XPS). Furthermore, the anti-corrosion performance for studied PILs aggregates is shown by the polarization curves and the impedance spectroscopy. As a result, the target PILs aggregates show great corrosion inhibition performance to copper in aggressive acid medium.