Ammonium Phosphate as Inhibitor to Mitigate the Corrosion of Steel Rebar in Chloride Contaminated Concrete Pore Solution
In the present study, different amounts, i.e., 1–3 <i>v</i>/<i>v</i>% of 1 M ammonium phosphate monobasic, were used as an eco-friendly corrosion inhibitor to mitigate the corrosion of steel rebar exposed to simulated concrete pore (SCP) + 3.5 wt% NaCl solution at a prolonged...
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MDPI AG
2020-08-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/25/17/3785 |
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| author | Soumen Mandal Jitendra Kumar Singh Dong-Eun Lee Taejoon Park |
| author_facet | Soumen Mandal Jitendra Kumar Singh Dong-Eun Lee Taejoon Park |
| author_sort | Soumen Mandal |
| collection | DOAJ |
| description | In the present study, different amounts, i.e., 1–3 <i>v</i>/<i>v</i>% of 1 M ammonium phosphate monobasic, were used as an eco-friendly corrosion inhibitor to mitigate the corrosion of steel rebar exposed to simulated concrete pore (SCP) + 3.5 wt% NaCl solution at a prolonged duration. Potentiodynamic polarization results show that as the amount of inhibitor is increased, the corrosion resistance of steel rebar is increased. The steel rebar exposed to 3% inhibitor-containing SCP + 3.5 wt% NaCl solution exhibited nobler corrosion potential (<i>E<sub>corr</sub></i>), the lowest corrosion current density (<i>i<sub>corr</sub></i>), and 97.62% corrosion inhibition efficiency after 1 h of exposure. The steel rebars exposed to 3% inhibitor-containing SCP + 3.5 wt% NaCl solution revealed higher polarization resistance (<i>R<sub>p</sub></i>) and film resistance (<i>R<sub>o</sub></i>) with exposure periods compared to other samples owing to the formation of passive film. The scanning electron microscopy (SEM) of steel rebar exposed to 3% inhibitor-containing SCP + 3.5 wt% NaCl solution showed homogenous and uniform dendritic passive film which covers all over the surface, whereas, bare, i.e., SCP + 3.5 wt% NaCl solution exposed samples exhibited pitting and irregular morphology. Raman spectroscopy results confirm the formation of goethite (α-FeOOH), maghemite (γ-Fe<sub>2</sub>O<sub>3</sub>), and iron phosphate (FePO<sub>4</sub>) as a passive film onto the steel rebar surface exposed to 3% inhibitor-containing SCP + 3.5 wt% NaCl solution. These phases are responsible for the corrosion mitigation of steel rebar which are very protective, adherent, and sparingly soluble. |
| first_indexed | 2024-03-10T17:07:47Z |
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| language | English |
| last_indexed | 2024-03-10T17:07:47Z |
| publishDate | 2020-08-01 |
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| series | Molecules |
| spelling | doaj.art-511a1b557478480c8cee7326962c7d8d2023-11-20T10:45:30ZengMDPI AGMolecules1420-30492020-08-012517378510.3390/molecules25173785Ammonium Phosphate as Inhibitor to Mitigate the Corrosion of Steel Rebar in Chloride Contaminated Concrete Pore SolutionSoumen Mandal0Jitendra Kumar Singh1Dong-Eun Lee2Taejoon Park3Intelligent Construction Automation Center, Kyungpook National University, 80, Daehak-ro, Buk-gu, Daegu 41566, KoreaInnovative Durable Building and Infrastructure Research Center, Department of Architectural Engineering, Hanyang University, 1271 Sa3-dong, Sangrok-gu, Ansan 15588, KoreaSchool of Architecture, Civil, Environment, and Energy, Kyungpook National University, 1370, Sangyegk-Dong, Buk-Gu, Daegu 702-701, KoreaDepartment of Robotics Engineering, Hanyang University, 55 Hanyangdaehak-ro, Ansan, Gyeonggi-do 15588, KoreaIn the present study, different amounts, i.e., 1–3 <i>v</i>/<i>v</i>% of 1 M ammonium phosphate monobasic, were used as an eco-friendly corrosion inhibitor to mitigate the corrosion of steel rebar exposed to simulated concrete pore (SCP) + 3.5 wt% NaCl solution at a prolonged duration. Potentiodynamic polarization results show that as the amount of inhibitor is increased, the corrosion resistance of steel rebar is increased. The steel rebar exposed to 3% inhibitor-containing SCP + 3.5 wt% NaCl solution exhibited nobler corrosion potential (<i>E<sub>corr</sub></i>), the lowest corrosion current density (<i>i<sub>corr</sub></i>), and 97.62% corrosion inhibition efficiency after 1 h of exposure. The steel rebars exposed to 3% inhibitor-containing SCP + 3.5 wt% NaCl solution revealed higher polarization resistance (<i>R<sub>p</sub></i>) and film resistance (<i>R<sub>o</sub></i>) with exposure periods compared to other samples owing to the formation of passive film. The scanning electron microscopy (SEM) of steel rebar exposed to 3% inhibitor-containing SCP + 3.5 wt% NaCl solution showed homogenous and uniform dendritic passive film which covers all over the surface, whereas, bare, i.e., SCP + 3.5 wt% NaCl solution exposed samples exhibited pitting and irregular morphology. Raman spectroscopy results confirm the formation of goethite (α-FeOOH), maghemite (γ-Fe<sub>2</sub>O<sub>3</sub>), and iron phosphate (FePO<sub>4</sub>) as a passive film onto the steel rebar surface exposed to 3% inhibitor-containing SCP + 3.5 wt% NaCl solution. These phases are responsible for the corrosion mitigation of steel rebar which are very protective, adherent, and sparingly soluble.https://www.mdpi.com/1420-3049/25/17/3785steelcorrosioninhibitorconcretepotentiodynamic polarizationelectrochemical impedance spectroscopy |
| spellingShingle | Soumen Mandal Jitendra Kumar Singh Dong-Eun Lee Taejoon Park Ammonium Phosphate as Inhibitor to Mitigate the Corrosion of Steel Rebar in Chloride Contaminated Concrete Pore Solution Molecules steel corrosion inhibitor concrete potentiodynamic polarization electrochemical impedance spectroscopy |
| title | Ammonium Phosphate as Inhibitor to Mitigate the Corrosion of Steel Rebar in Chloride Contaminated Concrete Pore Solution |
| title_full | Ammonium Phosphate as Inhibitor to Mitigate the Corrosion of Steel Rebar in Chloride Contaminated Concrete Pore Solution |
| title_fullStr | Ammonium Phosphate as Inhibitor to Mitigate the Corrosion of Steel Rebar in Chloride Contaminated Concrete Pore Solution |
| title_full_unstemmed | Ammonium Phosphate as Inhibitor to Mitigate the Corrosion of Steel Rebar in Chloride Contaminated Concrete Pore Solution |
| title_short | Ammonium Phosphate as Inhibitor to Mitigate the Corrosion of Steel Rebar in Chloride Contaminated Concrete Pore Solution |
| title_sort | ammonium phosphate as inhibitor to mitigate the corrosion of steel rebar in chloride contaminated concrete pore solution |
| topic | steel corrosion inhibitor concrete potentiodynamic polarization electrochemical impedance spectroscopy |
| url | https://www.mdpi.com/1420-3049/25/17/3785 |
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