Abstract
The hydrophobic characteristic of corrosion inhibitors increases inhibition efficiency and lowers corrosion rates by promoting better adsorption onto metal surfaces and forming a more effective barrier against corrosive substances. In this study, three AMCs with varying hydrophobic properties were tested to examine their capacity to suppress P110 CS corrosion in 15% HCl is studied. The electrochemical studies demonstrated that AMCs with hydrophilic and hydrophobic ratios of 100, 90:10, and 80:20 showed the %IE of 87.74%, 92.12%, and 93.53%, respectively. The OCP and PDP studies demonstrate that AMCs effectively replace the pre-adsorbed water molecules at the active areas of the metallic surface as mixed-type corrosion inhibitors because they prevent both anodic and cathodic reactions without appreciably changing the corrosion potential. They work by forming a corrosion-inhibiting coating on the metal surface through adsorption, based on the Langmuir isotherm concept. The results of the DFT analysis indicate that the adsorption and charge-sharing processes involve significant involvement from quaternary nitrogen atoms of hydrophilic and hydrophobic moieties. Finally, a schematic representation based on the concept from electrochemical, surface, and computational research is used to explain the corrosion inhibition mechanism of AMCs.
