The Blue Tansy Essential Oil–Petra/Osiris/Molinspiration (POM) Analyses and Prediction of Its Corrosion Inhibition Performance Based on Chemical Composition

Round 1

Reviewer 1 Report

Please see the attached file 

Comments for author File: Comments.pdf

Author Response

Response to Reviewer # 1 Comments:

 

1. Please check the grammatical error throughout the manuscript.

 

RESPONSE: The grammatical error was checked and corrected as suggested by the reviewer.

2. Lot of work was done in this area, in your study provide novelty of the work in the abstract and compare with previous research.

 

RESPONSE: The novelty of the work lies in the use of Petra/Osiris/Molinspiration (POM) analyses to gain insights into the risk of toxicity and their bioactivity score of all of the constituents of the BTES. This has been highlighted in the abstract in comparison to previous research.

 

3. After the corrosion, please provide SEM images.

 

RESPONSE : Unfortunately, we cannot carry out SEM/EDS studies because the BTES 1 has degraded, and we could not find a Tansy essential oil with the same chemical composition to complete the comparison of the results of the two essential oils. We want to appeal for understanding and to consider the manuscript as it is currently presented.

 

4. Please provide impedance data and circuit diagram.

 

RESPONSE : Unfortunately, we cannot carry out EIS studies because the BTES 1 has degraded, and we could not find a Tansy essential oil with the same chemical composition to complete the comparison of the results of the two essential oils. The impedance analyzes were carried out on BTES 2 and the results of this study are the subject of a scientific article which has been accepted for publication. We want to appeal for understanding and to consider the manuscript as it is currently presented.

 

5. In introduction part, refer and cite, these article

• Corrosion Inhibition Effect of Ethyl 1-(4-chlorophenyl)-5-methyl-1H-1,2,3-triazole-4 carboxylate on Aluminium Alloy in Hydrochloric Acid, Protection of Metals and Physical Chemistry of Surfaces, 57, 2021, 181-189.
• Electrochemical and Quantum Chemical Studies of 5-[(4-Chlorophenoxy) Methyl]-4H-1,2,4-Triazole-3-Thiol on the Corrosion Inhibition of 6061 Al Alloy in Hydrochloric Acid, J Fail. Anal. and Preven. 20 (5), 2020,1598-1608

RESPONSE : The two suggested articles has been cited in the introduction section of the manuscript (see reference 5 and 6).

Reviewer 2 Report

In the present work, the corrosion inhibition performance of two Blue Tansy essential oils (BTES 1 and BTES 2) as sustainable corrosion inhibitor having different chemical compositions was evaluated. The corrosion-resistance ability of the BTES for mild in 1 M HCl was evaluated by means of weight loss and Potentiodynamic polarization techniques. 

 

I had carefully revised the manuscript and my decision is to be revised with major revisions.

 

Comments:

1-   Abstract part needs to be rewritten to include identically 3 brief informative subheadings, background, methods, and especially significant findings from the applied characteristic methods.

2-   Introduction should be modified with additional literature survey related to the subject of the present research ( corrosion inhibition of some green inhibitors with sustainable resource).

3-   Several characterization methods for briefly detection of the structure consistence of the utilized extracted Blue Tansy essential oils (BTES 1 and BTES 2) such as GC mass spectroscopy.  

4-   The results part is displayed with so poor data discussions, so more discussions must be added to support the obtained results especially the interpretation data of microstructure investigations part.

5-   For complete and intrinsic electrochemical behavior of the Blue Tansy essential oils (BTES 1 and BTES 2) in 1 M HCl as aggressive medium, electrochemical impedance spectroscopy (EIS), should be incorporated to detect the charge transfer resistance (R_ct) of the formed thin layer on the C-steel surface.

6-   The surface morphology of the immersion for blank C-steel coupons against the inhibited ones at different inhibitor concentrations at 1 M HCl as aggressive medium using SEM, and EDX must be incorporated in addition to performing XPS measurements.

7-   An expected mechanism for the inhibition efficiency of the effective moieties of the Blue Tansy essential oils (BTES 1 and BTES 2) on the C-steel vacant orbital should be offered and sketched.

8-   English language needs modification with the help of an English editing service or native or expert person in English language.

 

  

 

 

 

 

 Moderate editing of English language required

Author Response

Response to Reviewer # 2 Comments:

1. Abstract part needs to be rewritten to include identically 3 brief informative subheadings, background, methods, and especially significant findings from the applied characteristic methods.

RESPONSE : This has been done as suggested by the reviewer.

2. Introduction should be modified with additional literature survey related to the subject of the present research (corrosion inhibition of some green inhibitors with sustainable resource).

RESPONSE : This has been done (see reference 7 and 8)

3. Several characterization methods for briefly detection of the structure consistence of the utilized extracted Blue Tansy essential oils (BTES 1 and BTES 2) such as GC mass spectroscopy.

RESPONSE :  This comment is not clear. We use GC-MS to determine the chemical composition of both BTES 1 and BTES 2. However, given that we did not isolate individual components, the structure of individual constituents cannot be determined in the present work. It is in our plan to do that in the future.

4. The results part is displayed with so poor data discussions, so more discussions must be added to support the obtained results especially the interpretation data of microstructure investigation’s part.

RESPONSE: We have tried to improve the discussion as suggested by the reviewer. We have a detailed discussion of the results obtained by the POM analysis.

5. For complete and intrinsic electrochemical behavior of the Blue Tansy essential oils (BTES 1 and BTES 2) in 1 M HCl as aggressive medium, electrochemical impedance spectroscopy (EIS), should be incorporated to detect the charge transfer resistance (R_ct) of the formed thin layer on the C-steel surface.

RESPONSE : Unfortunately, we cannot carry out EIS studies because the BTES 1 has degraded, and we could not find a Tansy essential oil with the same chemical composition to complete the comparison of the results of the two essential oils. The impedance analyzes were carried out on BTES 2 and the results of this study are the subject of a scientific article which has been accepted for publication. We want to appeal for understanding and to consider the manuscript as it is currently presented.

6. The surface morphology of the immersion for blank C-steel coupons against the inhibited ones at different inhibitor concentrations at 1 M HCl as aggressive medium using SEM, and EDX must be incorporated in addition to performing XPS measurements.

RESPONSE : Unfortunately, we cannot carry out SEM/EDS or XPS studies because the BTES 1 has degraded, and we could not find a Tansy essential oil with the same chemical composition to complete the comparison of the results of the two essential oils. We want to appeal for understanding and to consider the manuscript as it is currently presented.

7. An expected mechanism for the inhibition efficiency of the effective moieties of the Blue Tansy essential oils (BTES 1 and BTES 2) on the C-steel vacant orbital should be offered and sketched.

RESPONSE : At this stage proposing corrosion inhibition mechanism will be speculative given that we have not been able to pinpoint which of the constituent(s) of the essential oils is/are actually responsible for the observed corrosion inhibition mechanism given that the essential oils are composed of myriad of organic compounds as could be seen in Table 1. It is our plan in the future to isolate individual components of the essential oils and carry out corrosion inhibition studies of the individual isolates. By then it will be appropriate to propose the plausible corrosion inhibition mechanism since the actual compounds responsible for the corrosion inhibition will be known.

8. English language needs modification with the help of an English editing service or native or expert person in English language.

RESPONSE : The English language of the manuscript has been modified as suggested by the reviewer.

Reviewer 3 Report

It seems the manuscript has been thoroughly revised, so no further comments.

Conclusion part can be improved more better 

No comments

Author Response

It seems the manuscript has been thoroughly revised, so no further comments.

Conclusion part can be improved more better.

RESPONSE: We want to thank the reviewer for the commendation. The conclusion part has been improved as suggested which is also in line with the suggestion of Reviewer #4.

Reviewer 4 Report

This study investigates the corrosion inhibition potential of two distinct Blue Tansy essential oils 21 (BTES 1 and BTES 2) with different chemical compositions for mild steel in 1M HCl. This work is interesting; however, the following points should be appropriately addressed before publication.

1.       Table 2 shows that there are many phytochemicals present in the extract, of course, some of them are present in relatively larger proportions. Is there any way to determine the contribution of different constituents in corrosion mitigation?

2.       The different constituents may have synergistic or antagonistic effects on corrosion mitigation. Please add commentaries to it.

3.        If the highest %IE was obtained at 0.5 ppm, why not tests conducted at lower concentrations like 0.2 ppm and 0.1 ppm?

4.       Why %IEs are decreasing with the rise in concentration? Please add justification and cite suitable references.

5.       Please also provide challenges and opportunities related to your work in the last portion of the conclusion (very short).  

Author Response

Response to Reviewer #4 Comments

This study investigates the corrosion inhibition potential of two distinct Blue Tansy essential oils 21 (BTES 1 and BTES 2) with different chemical compositions for mild steel in 1M HCl. This work is interesting; however, the following points should be appropriately addressed before publication.

1. Table 2 shows that there are many phytochemicals present in the extract, of course, some of them are present in relatively larger proportions. Is there any way to determine the contribution of different constituents in corrosion mitigation?

RESPONSE: We want to thank the reviewer for this comment. At the moment we cannot pinpoint the contribution of the different constituents on the observed corrosion mitigation. However, it is our future plan to isolate some of the constituents (particularly those present in relatively larger amount) or obtain the commercially available compounds and evaluate their corrosion mitigation potentials and then compare to the extract. By then, it will be clear the individual contribution of the constituents to corrosion mitigation.

2. The different constituents may have synergistic or antagonistic effects on corrosion mitigation. Please add commentaries to it.

RESPONSE: Thank you for the comment. This has been added to the revised manuscript.

3. If the highest %IE was obtained at 0.5 ppm, why not tests conducted at lower concentrations like 0.2 ppm and 0.1 ppm?

RESPONSE: The lowest concentration used was 0.5 g/L (that is 500 ppm) and not 0.5 ppm as indicated by the reviewer. The optimum IE was obtained at 0.5 g/L concentration for BTES 1 and not for BTES 2. Given that we are doing comparative studies of the two essential oils of different composition, it will not be ideal to conduct the test at lower concentrations like 0.1 g/L and 0.2 g/L as suggested by the reviewer.

4. Why %IEs are decreasing with the rise in concentration? Please add justification and cite suitable references.

RESPONSE: It is not entirely correct that IE is decreasing with increase in concentration. The true picture is that IE rise and fall with increase in concentration for BTES 1 following a damped oscillation and for BTES 2, it is observed that IE initially fall with rise in concentration and thereafter rise with rise in concentration. We have tried to explain the probable reason for this observation. This phenomenon is not common in corrosion inhibition literature and seems peculiar to the studied essential oils.

5. Please also provide challenges and opportunities related to your work in the last portion of the conclusion (very short).  

RESPONSE: This has been done.

 

Round 2

Reviewer 2 Report

Authors didnot cover the required comments and the paper can not be accepted except covering the all required comments.

Author Response

Authors did not cover the required comments and the paper can not be accepted except covering the all required comments.

Response: It is not known which of the reviewers' comments was not covered in our earlier responses. The reviewer should has a matter of clarity point out the comment(s) which he/she feels has/have not been adequately addressed. 

We hereby reproduced the earlier reviewer's comments and our responses.

Response to Reviewer # 2 Comments:

• Abstract part needs to be rewritten to include identically 3 brief informative subheadings, background, methods, and especially significant findings from the applied characteristic methods.

RESPONSE : This has been done as suggested by the reviewer.

• Introduction should be modified with additional literature survey related to the subject of the present research (corrosion inhibition of some green inhibitors with sustainable resource).

RESPONSE : This has been done (see reference 7 and 8)

• Several characterization methods for briefly detection of the structure consistence of the utilized extracted Blue Tansy essential oils (BTES 1 and BTES 2) such as GC mass spectroscopy.

RESPONSE :  This comment is not clear. We use GC-MS to determine the chemical composition of both BTES 1 and BTES 2. However, given that we did not isolate individual components, the structure of individual constituents cannot be determined in the present work. It is in our plan to do that in the future.

• The results part is displayed with so poor data discussions, so more discussions must be added to support the obtained results especially the interpretation data of microstructure investigation’s part.

RESPONSE: We have tried to improve the discussion as suggested by the reviewer. We have a detailed discussion of the results obtained by the POM analysis.

• For complete and intrinsic electrochemical behavior of the Blue Tansy essential oils (BTES 1 and BTES 2) in 1 M HCl as aggressive medium, electrochemical impedance spectroscopy (EIS), should be incorporated to detect the charge transfer resistance (R_ct) of the formed thin layer on the C-steel surface.

RESPONSE : Unfortunately, we cannot carry out EIS studies because the BTES 1 has degraded, and we could not find a Tansy essential oil with the same chemical composition to complete the comparison of the results of the two essential oils. The impedance analyzes were carried out on BTES 2 and the results of this study are the subject of a scientific article which has been accepted for publication. We want to appeal for understanding and to consider the manuscript as it is currently presented.

• The surface morphology of the immersion for blank C-steel coupons against the inhibited ones at different inhibitor concentrations at 1 M HCl as aggressive medium using SEM, and EDX must be incorporated in addition to performing XPS measurements.

RESPONSE : Unfortunately, we cannot carry out SEM/EDS or XPS studies because the BTES 1 has degraded, and we could not find a Tansy essential oil with the same chemical composition to complete the comparison of the results of the two essential oils. We want to appeal for understanding and to consider the manuscript as it is currently presented.

• An expected mechanism for the inhibition efficiency of the effective moieties of the Blue Tansy essential oils (BTES 1 and BTES 2) on the C-steel vacant orbital should be offered and sketched.

RESPONSE : At this stage proposing corrosion inhibition mechanism will be speculative given that we have not been able to pinpoint which of the constituent(s) of the essential oils is/are actually responsible for the observed corrosion inhibition mechanism given that the essential oils are composed of myriad of organic compounds as could be seen in Table 1. It is our plan in the future to isolate individual components of the essential oils and carry out corrosion inhibition studies of the individual isolates. By then it will be appropriate to propose the plausible corrosion inhibition mechanism since the actual compounds responsible for the corrosion inhibition will be known.

• English language needs modification with the help of an English editing service or native or expert person in English language.

RESPONSE : The English language of the manuscript has been modified as suggested by the reviewer.

Round 3

Reviewer 2 Report

Authors didnot perform the requird changes and the manuscript can not be considered for publication for  in this journal except all required comments were covered.

Minor English Editing can be made.