Potential of Borage flower aqueous extract as an environmentally sustainable corrosion inhibitor for acid corrosion of mild steel: Electrochemical and theoretical studies

Publication date: 1 March 2019Source: Journal of Molecular Liquids, Volume 277Author(s): Ali Dehghani, Ghasem Bahlakeh, Bahram Ramezanzadeh, Mohammad RamezanzadehAbstractThe presence of numerous active compounds like lactic acid, nicotinic acid, and carotene in the Borage flower extract (BFE) converted it to a potent source of powerful sustainable compounds for mild steel (MS) corrosion mitigation in the solution of 1 M hydrochloric acid. The corrosion inhibition mechanism was assessed by potentiodynamic polarization (PPL) and the impact of inhibitor content and exposure time on the inhibition extent of the BFE was investigated by electrochemical impedance spectroscopy (EIS). Different constituents of Borage flower extract were examined by FT-IR and UV–Vis methods. Surface morphology was studied by AFM and SEM analyses, and the surface hydrophilicity/hydrophobicity was assessed by contact angle test. EIS findings evidenced that with the increase in Borage flower extract content in HCl solution and immersion time the power of corrosion prevention increased in HCl environment and achieved the highest value of 91% at 800 ppm after 5 h. On the basis of polarization curves it was found that the Borage flower extract showed a mixed effect in corrosion inhibition with a minor cathodic prevalence. The SEM and AFM examinations demonstrated that the adsorption of BFE components on the MS surface gave rise to a smooth surface morphology with few damaged areas. The analysis of co...
Source: Journal of Molecular Liquids - Category: Molecular Biology Source Type: research