Morphological performances and corrosion inhibition mechanism of new amphiphilic tetra-cationic imidazolium ionic liquids for carbon steel in 1M HCl medium

Abstract

BackgroundRoom temperature liquids based on amphiphilic imidazolium ionic liquids (AImILs) with superior surface properties in acidic aqueous solutions form stable thin film on the surface of steel attracted great attention to apply as green corrosion inhibitors at different temperatures. MethodsTetra-cationic ionic liquids 2-(4-dodecyldimethylamino) phenyl)-1,3-bis (3-dodecyldimethylammnonio) propyl) bromide-1-H-imidazol-3-ium acetate (DDAP-ImA) and 2-(4-hexyldimethylamino) phenyl)-1,3-bis(3-hexcyldimethylammnonio) propyl) bromide-1 H-imidazol-3-ium acetate (HDAP-ImA) were prepared with higher reaction yields using two steps technique. The corrosion inhibition efficiencies of the prepared ImILs for steel surface in 1 M HCl were evaluated at different temperature using different techniques. Significant findingsThe data confirm that lower concentrations of DDAP-ImA achieved higher corrosion inhibition efficiencies based on physio-chemical mechanism on the steel surface with the formation of linked and adsorbed layers on the steel surfaces even at lower concentrations that confirmed from the standard free energy. Surface morphologies (SEM, AFM) indicated that more homogeneous surface and metallic interfaces in the presence of HDAP-ImA and DDAP-ImA were formed more than blank and in the presence of DPAP-ImA. This protective homogeneous film limits the transfer of active corrosive species towards the steel surface which was rationalized in an inhibition mechanism.