Exploration of Sunflower Oil As a Renewable Biomass Source to Develop Scalable and Highly Effective Corrosion Inhibitors in a 15% HCl Medium at High Temperatures

The feasibility study of utilizing sunflower oil as renewable biomass source to develop highly effective inhibitors for mild steel corrosion (MS) in the 15% HCl medium was done by weight loss, potentiodynamic polarization (PDP), dynamic electrochemical impedance spectroscopy (DEIS), and electrochemical impedance spectroscopy (EIS), supported with energy-dispersive X-ray (EDX), atomic force microscopy (AFM), and field-emission scanning electron microscope (FESEM) techniques. Moreover, a complementary theoretical investigation was carried out to clarify the inhibition mechanism of inhibitors by density functional theory (DFT), density functional based tight-binding (DFTB), and molecular dynamics (MD) simulation approaches. The obtained results confirm that sunflower-oil-based corrosion inhibitor (SFOCI) has a significant anticorrosion property toward the dissolution of MS in 15% HCl solution in the temperature range 20-80 degrees C. In addition, the results show that SFOCI could provide an inhibition efficiency of 98 and 93% at 60 and 80 degrees C, respectively. The inhibition mechanism of SFOCIs was mixed-type and their adsorption on the surface of MS was mainly chemisorption. The FESEM and EDX studies proved the presence of SFOCI molecules on the surface of MS. In addition, the adsorption energy of SFOCI indicated an intense interaction between the inhibitor and surface of Fe. The results of this study could open a new window for the design and development of scalable and effective ecofriendly vegetable-oil-based corrosion inhibitors for highly corrosive solutions at high temperatures.

Automated summary

This study investigates the feasibility of using sunflower oil to develop highly effective inhibitors for mild steel corrosion in 15% HCl medium. The results show that the sunflower-oil-based corrosion inhibitor (SFOCI) has significant anticorrosion properties, with inhibition efficiencies of 98% and 93% at temperatures of 60 and 80 degrees Celsius, respectively. The mechanism of inhibition is mixed-type with mainly chemisorption onto the surface of mild steel. The study suggests a potential new direction for designing eco-friendly vegetable-oil-based corrosion inhibitors for highly corrosive solutions at high temperatures.