Experimental and computational studies on hydroxamic acids as environmental friendly chelating corrosion inhibitors for mild steel in aqueous acidic medium
| Autor: | Dakeshwar Kumar Verma, Ashish Asatkar, Fahmida Khan, Eno E. Ebenso, Chandrabhan Verma, Chaudhery Mustansar Hussain, Akram Al Fantazi |
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| Rok vydání: | 2020 |
| Předmět: |
02 engineering and technology
010402 general chemistry 01 natural sciences Corrosion Metal symbols.namesake Adsorption Materials Chemistry medicine Physical and Theoretical Chemistry Conformational isomerism Spectroscopy Aqueous solution Chemistry Acetohydroxamic acid Langmuir adsorption model 021001 nanoscience & nanotechnology Condensed Matter Physics Tautomer Atomic and Molecular Physics and Optics 0104 chemical sciences Electronic Optical and Magnetic Materials visual_art visual_art.visual_art_medium symbols 0210 nano-technology medicine.drug Nuclear chemistry |
| Zdroj: | Journal of Molecular Liquids. 314:113651 |
| ISSN: | 0167-7322 |
| Popis: | In the present study, three hydroxamic acids (HAs) namely acetohydroxamic acid (AHA), benzohydroxamic acid (BHA) and oxalohydroxamic acid (OHA) were synthesized, characterized and used as inhibitors for mild steel corrosion in1 M HCl using chemical, electrochemical, surface and computational methods. Results of the studies show that the HAs act as effective corrosion inhibitors and their inhibition efficiencies follow the order: OHA (96.37%) > BHA (95.69%) > AHA (93.29%). EIS study showed that studied HAs act as interface type inhibitors. Polarization study revealed that HAs demonstrate mixed-type corrosion inhibitors characteristics and adsorb on the active sites of metallic surface. . Adsorption of HAs on metal-1 M HCl interfaces followed the Langmuir adsorption isotherm model. Surface morphological analyses of inhibited and uninhibited metallic surface were carried out using SEM-EDX and XRD methods. DFT analyses showed that studied compounds act as chelating type of ligands. Effect of Keto-enol tautomerism and different possible conformational isomers on metallic corrosion inhibition was demonstrated. The conformational isomers in which >C=O and –OH (hydroxyl) groups present in same side behave as chelating ligands and form relatively more stable complex than that of conformational isomers in which >C=O and –OH groups present in opposite side. Experimental and DFT studies complimented each other well. |
| Databáze: | OpenAIRE |
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