TAILORING ALKYL CHAIN LENGTH IN ISOQUINOLINIUM-BASED INHIBITORS: IMPACT ON ADSORPTION BEHAVIOR AND CORROSION PROTECTION IN OIL REFINING SYSTEMS

In this study, new corrosion inhibitors based on arylcarbonylmethylisoquinolinium chlorides were synthesized and evaluated for application in oil refining systems. The inhibition performance was investigated using electrochemical and gravimetric methods in model oilfield wastewater. The results revealed a strong dependence of corrosion inhibition efficiency on the alkyl chain length. The maximum efficiency (79.8%) was achieved for the compound containing 10 carbon atoms, indicating an optimal balance between hydrophobicity and solubility. Adsorption analysis showed that the inhibition process follows the Langmuir isotherm, suggesting monolayer adsorption of inhibitor molecules on the metal surface. The inhibition mechanism is governed by both electronic effects and molecular structure, leading to the formation of a stable protective film. The synthesized compounds demonstrate high potential as effective corrosion inhibitors for oil refining and transportation systems