Corrosion Behaviors of Tetrasodium Iminodisuccinate (IDS) as an Environmentally Friendly Inhibitor: Experimental and Theoretical Studies
Round 1
Reviewer 1 Report
Mild correction in English is required.
Author Response
- why Open circuit potential values are stable in blank and more flactuations in presence of inhibitor?
Response: Thanks very much for your careful reading of our manuscript. This phenomenon is a manifestation of the protective effect of the inhibitor, and the fundamental reason is the competitive balance between the promotion of the inhibitor's protective film formation by hydroxide ions and the attack of the protective film by chloride ions. Specifically, the corrosion medium in the blank solution continuously corrodes the steel, so the corrosion potential has been moving negatively. However, the solution containing the inhibitor IDS has a protective effect on the steel, so at the beginning, the corrosion potential moves towards the positive direction. But due to the high content of chloride ions (in this work, [Cl-]/[OH-] is about 0.7, far exceeding its critical value of 0.1), the steel eventually corrodes and gradually drifts towards the negative direction, stabilizing at around 3600 seconds. In addition, the difference in surface roughness or composition of the steel samples causes significant differences in the variation of the corrosion potential with time, but the final stable corrosion potential increases with the concentration of IDS. The corrosion potential of the steel in the blank solution is the lowest, indicating the most severe corrosion.
2.what is the information you will share with us by taking EDS?
Response: Thanks very much for your careful reading of our manuscript. After immersion in a 200 mg/L inhibitor solution, the surface of the steel contained a higher proportion of carbon, which is attributed to the presence of carbon in the adsorbed inhibitor molecules. Additionally, the decrease in oxygen and chlorine indicates that the active sites for the corrosive particles that would normally adsorb have been occupied by inhibitor molecules. These results were further supported by EDS analysis, which confirms the adsorption of inhibitor molecules on the surface of the steel.
- your inhibition efficiency at 328K is around 85%. why you have go beyond this temperature study the inhibitor effect?
Response: Thanks very much for your careful reading of our manuscript. We designed a series of temperature gradients to investigate the effect of temperature on the corrosion inhibition efficiency of the inhibitor, as the corrosion process of steel and the process of inhibitor preventing steel from corroding are closely related to temperature. Our goal is to prevent the failure of steel bars in reinforced concrete structures due to corrosion, which could lead to economic losses and safety accidents. In the summer, the temperature of reinforced concrete structures in northwest China may reach 328K, which is the possible working environment temperature of the inhibitor. We aim to find a green and efficient corrosion inhibitor that can inhibit the corrosion of steel bars at high temperatures. In addition, to gain a more comprehensive understanding of IDS as a corrosion inhibitor, we tested its inhibition efficiency at 328K.
- Authors can quote these papers in the reference to get more weightage in this paper.
Response: Thanks for the reviewer’s comment. We have included the recommended references in the introduction section (Ref [3-5], [7] and [10]). These literatures are indeed helpful to strengthen the research background review and also make our manuscript more integrity and accurate.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Dear Authors,
Overall work is good.
1. why Open circuit potential values are stable in blank and more flactuations in presence of inhibitor?
2. what is the information you will share with us by taking EDS
3 your inhibition efficiency at 328K is around 85%. why you have go beyond this temperature study the inhibitor effect
4. Authors can quote these papers in the reference to get more weightage in this paper
Anti-Corrosion Behavior of Olmesartan for Soft-Cast Steel in 1 mol dm−3 HCl BM Praveen, A Alhadhrami, BM Prasanna, N Hebbar, R Prabhu
Coatings 11 (8), 965 https://doi.org/10.3390/coatings11080965
Ketosulfone Drug as a Green Corrosion Inhibitor for Mild Steel in Acidic Medium
HCT PB Matad, Praveen B Mokshanatha, N Hebbar, VT Venkatesha Industrial & Engineering Chemistry Research 53 (20), 8436-8444 53 (20), https://doi.org/10.1021/ie500232g
Investigation of African mangosteen leaves extract as an environment-friendly inhibitor for low carbon steel in 0.5 M H2SO4 MR Rathod, SK Rajappa, RL Minagalavar, BM Praveen, BK Devendra, ... Inorganic Chemistry Communications 140, 109488 https://doi.org/10.1016/j.inoche.2022.109488
Investigation of anticorrosive behaviour of novel tert-butyl 4-[(4-methyl phenyl) carbonyl] piperazine-1-carboxylate for carbon steel in 1M HClBM Praveen, BM Prasanna, NM Mallikarjuna, MR Jagadeesh, N Hebbar, ...Heliyon 7 (2), e06090 https://doi.org/10.1016/j.heliyon.2021.e06090
Electrochemical and adsorption studies of 4-chloro, 8-(trifluoromethyl) quinoline (CTQ) for mild steel in acidic medium
N Hebbar, BM Praveen, BM Prasanna, P VishwanathJournal of Failure Analysis and Prevention 20, 1516-1523https://doi.org/10.1007/s11668-020-00944-4
Author Response
1.Electrochemical impedance spectroscopy from Figure 3a as Nyquist representation has to be ortho normed. Please write the Impedance equation and correct OX and OY axes. For example: If your OX axe has 2 cm for 5 kohm cm2, the same values must be on OY axe.5 kohm cm2 must have the same length of 2 cm.
The impedance associated with the X-axis is referred to as the real impedance, Real Z, and the impedance associated with the Y-axis is referred to as the imaginary impedance, -Im Z. The Bode plots from Figure 3 b are not correct also.
Representation of Impedance modulus |Z| in logarithmic scale versus logaritm of frequency must be on OY axe. For the phase angle the values are negative from EIS measurements.
Response: Thanks very much for your careful reading of our manuscript. According to your suggestion, we have made the change in the revised manuscript. The modified Figure 3 is as follows:
Figure 3. Nyquist (a) and Bode (b) plots of Q235 carbon steel.
Eq. 16 in the original text is shown below:
|
(16) |
|
|
The modified Eq. 16 is as follows: |
|
|
(16) |
2.The Table 2 caption show the impedance parameters of Q235 carbon steel after fitting the EIS results with a proposed electrical equivalent circuit.
The Table 3 caption is wrong and cannot show as is written in the "Table 3. Impedance parameters of Q235 carbon steel after fitted".
Table 3 must show the parameters resulted from Tafel polarization curves.
Response: Thanks very much for your careful reading of our manuscript. According to your suggestion, we have amended the title of Table 3 to be "Table 3. The polarization curve parameters of Q235 steel with different concentrations of IDS".v
Author Response File: Author Response.docx
Reviewer 3 Report
Reviewer Comments
Manuscript ID: coatings-226841
Corrosion behaviors of Tetrasodium iminodisuccinate (IDS) as an environmentally friendly inhibitor: Experimental and theoretical studies.
Special Issue: Advanced Corrosion Protection through Coatings and Surface Rebuilding
The paper presents the investigation of an environmentally friendly chelating agent, tetrasodium iminodisuccinate (IDS), as an inhibitor in the simulated concrete pore solution on Q235 carbon steel by using Tafel polarization (TF), electrochemical impedance spectroscopy (EIS) and surface morphology tests.
Some corrections have to be made as follow:
1. Electrochemical impedance spectroscopy from Figure 3a as Nyquist representation has to be ortho normed. Please write the Impedance equation and correct OX and OY axes. For example: If your OX axe has 2 cm for 5 kohm cm2, the same values must be on OY axe. 5 kohm cm2 must have the same length of 2 cm.
The impedance associated with the X-axis is referred to as the real impedance, Real Z, and the impedance associated with the Y-axis is referred to as the imaginary impedance, - Im Z. The Bode plots from Figure 3 b are not correct also.
Representation of Impedance modulus 
in logarithmic scale versus logaritm of frequency must be on OY axe. For the phase angle the values are negative from EIS measurements.
2. The Table 2 caption show the impedance parameters of Q235 carbon steel after fitting the EIS results with a proposed electrical equivalent circuit.
The Table 3 caption is wrong and cannot show as is written in the "Table 3. Impedance parameters of Q235 carbon steel after fitted".
Table 3 must show the parameters resulted from Tafel polarization curves.
In conclusion: The paper cannot be published in this form, the corrections must be done.
Comments for author File: 
Comments.pdf
Author Response
Response: Thanks very much for your careful reading of our manuscript. We have carefully revised and done our best to improve the language of the article. We hope that the level of language in the revised manuscript will meet the requirements of the reviewers.
Author Response File: Author Response.docx
