Hybrid Zinc-Based Multilayer Systems with Improved Protective Ability against Localized Corrosion Incorporating Polymer-Modified ZnO or CuO Particles
Round 1
Reviewer 1 Report
The manuscript entitled "Hybrid Zinc-Based Coatings with Improved Protective Ability Against Localized Corrosion and Biofouling" (MS#: coatings-1374763) is a research article claiming the designing of a new anti-corrosion and anti-biofouling coating for steel protection.
New and effective anti-corrosion and anti-biofouling surface coatings are of ongoing interest. So, the selected topic deserves attention. However, this manuscript severely suffers from several issues, which are outlined below (4 items):
1) ON MISMATCH OF SCOPE/TITLE AND CONTENT
The authors start their manuscript (in the Abstract) by reminding us that "Localized corrosion and biofouling cause very serious problems in the marine industries often related to financial losses and environmental accidents." Going further, they provide a lengthy paragraph on "biofouling" in the Introduction: "Biofouling is another great problem especially for marine structures leading to increased fuel consumption of ships, as well as to microbiologically induced corrosion degradation." And, there is nothing wrong with these statements. However, there is no actual content in the manuscript directly demonstrating the biofouling effect.
2) ON COATING DESIGN NOVELTY & FUNCTIONALITY
The authors embed a ZnO-PEI or CuO-PEI underneath a Zn layer to protect steel. There is nothing new in Zn coating. So, ZnO/CuO-PEI coating is the novel point, as implied in the manuscript. However, the authors already reported a very similar coating protocol before (ref. 34 in their manuscript). And, what is worse is that this supposedly antibiofouling layer is buried under a zinc layer, making it inaccessible, or the Zn layer becomes unnecessary if it is meant to die away fast under some specific expected conditions. Anyways, this coating is neither novel nor seemingly functional.
3) ON TEXT PLAGIARISM
Under the default settings of the software iThenticate, the text-similarity of the manuscript is staggeringly 31% (when the author names, affiliations, and generic texts, including the references, are excluded). The fourth and fifth paragraphs are almost entirely unoriginal, taken from an earlier publication of the same authors: "Composite coatings with polymeric modified ZnO nanoparticles and nanocontainers with inhibitor for corrosion protection of low carbon steel" by Kamburova et al., 2021, Colloids and Surfaces A, 609, 125741.) This is an unacceptable practice, including the self-plagiarism portion.
4) ON THE WRITING QUALITY
This manuscript is written carellesly, as evidenced by the existence of the remaining text in the Main Text: "Authors should discuss the results and how they can be interpreted from the perspective of previous studies and of the working hypotheses. The findings and their implications should be discussed in the broadest context possible. Future research directions may also be highlighted."
Besides, this manuscript also needs some careful editing. Some problems are listed below:
a) "... polymeric modified ..." --> "... polymer-modified ..."
b) "... It seems, that ..." --> "... It seems that..."
c) "... at 173 . …" --> ???
d) Smoluchowski equation --> components are missing!
FINAL REMARKS
Overall, this manuscript is very much incremental, and the content is too little and too insignificant to publish. Thus, unfortunately, I DO NOT SUPPORT the publication of this manuscript. I hope the authors benefit from this report.
Author Response
The manuscript entitled "Hybrid Zinc-Based Coatings with Improved Protective Ability Against Localized Corrosion and Biofouling" (MS#: coatings-1374763) is a research article claiming the designing of a new anti-corrosion and anti-biofouling coating for steel protection.
New and effective anti-corrosion and anti-biofouling surface coatings are of ongoing interest. So, the selected topic deserves attention. However, this manuscript severely suffers from several issues, which are outlined below (4 items):
1) ON MISMATCH OF SCOPE/TITLE AND CONTENT
The authors start their manuscript (in the Abstract) by reminding us that "Localized corrosion and biofouling cause very serious problems in the marine industries often related to financial losses and environmental accidents." Going further, they provide a lengthy paragraph on "biofouling" in the Introduction: "Biofouling is another great problem especially for marine structures leading to increased fuel consumption of ships, as well as to microbiologically induced corrosion degradation." And, there is nothing wrong with these statements. However, there is no actual content in the manuscript directly demonstrating the biofouling effect.
The reviewer's comment is taken into consideration. The title and some parts of the text have been changed and corrected.
2) ON COATING DESIGN NOVELTY & FUNCTIONALITY
The authors embed a ZnO-PEI or CuO-PEI underneath a Zn layer to protect steel. There is nothing new in Zn coating. So, ZnO/CuO-PEI coating is the novel point, as implied in the manuscript. However, the authors already reported a very similar coating protocol before (ref. 34 in their manuscript). And, what is worse is that this supposedly antibiofouling layer is buried under a zinc layer, making it inaccessible, or the Zn layer becomes unnecessary if it is meant to die away fast under some specific expected conditions. Anyways, this coating is neither novel nor seemingly functional.
Тhe authors do not share the view that there is nothing new with regard to zinc coating for the protection of low carbon steel and that this coating is not functional - the experimental results obtained show something completely different. To the best of our knowledge, zinc can be used as ordinary, alloy, composite or hybrid coating. The latter can be also applied as a “self-healing” one when, for example, nanocontainers filled with an inhibitor are incorporated therein. In our case, the coating containing polymer-modified CuO particles is intentionally placed under the ordinary zinc layer aiming to obtain additional protective effect after the dissolution of zinc and its corrosion products (which have a barrier effect) in order to hinder the penetrating of bioagents to the steel substrate. Our idea then was to obtain multilayer systems with under layer containing ZnO, CuO or both particles with combined action against corrosion and biofouling. At this stage we test the system against localized corrosion and we intend to continue our research concerning biofouling.
3) ON TEXT PLAGIARISM
Under the default settings of the software iThenticate, the text-similarity of the manuscript is staggeringly 31% (when the author names, affiliations, and generic texts, including the references, are excluded). The fourth and fifth paragraphs are almost entirely unoriginal, taken from an earlier publication of the same authors: "Composite coatings with polymeric modified ZnO nanoparticles and nanocontainers with inhibitor for corrosion protection of low carbon steel" by Kamburova et al., 2021, Colloids and Surfaces A, 609, 125741.) This is an unacceptable practice, including the self-plagiarism portion.
The authors do not accept this remark since they believe, it should be borne in mind that certain terms, methods, electrodes, etc. cannot be replaced (or it is very difficult and sometimes inappropriate) by other expressions or phrases.
In any case, the authors' aim was not to repeat their previous research, but to test their hypothesis as to the extent to which such systems could be obtained and to test their protective ability in a model environment with a view to further application against corrosion and eventually biofouling.
4) ON THE WRITING QUALITY
This manuscript is written carellesly, as evidenced by the existence of the remaining text in the Main Text: "Authors should discuss the results and how they can be interpreted from the perspective of previous studies and of the working hypotheses. The findings and their implications should be discussed in the broadest context possible. Future research directions may also be highlighted."
When submitting their manuscript the authors did not use the template. Most probably this accidental technical error occurred when transferring the text from the original file to the template. The mistake has been removed by the authors.
Besides, this manuscript also needs some careful editing. Some problems are listed below:
- a) "... polymeric modified ..." --> "... polymer-modified ..."
The text has been corrected.
- b) "... It seems, that ..." --> "... It seems that..."
The remark and the place of this mistake in the main text are unclear. However, the reviewer's comment is taken into consideration and text is checked for corrections.
- c) "... at 173 . …" --> ???
The remark and the place of this word combination are unclear. We suppose the reviewer means the text from Part 2.3., Page 4, Line 136-137:
– “A He-Ne laser is applied as a light source and the intensity of the scattered light is measured by a detector at 173”.
Most probably this accidental technical error occurred when transferring the text from the original file to the template. The text has been corrected as follows:
“A He-Ne laser is applied as a light source and the intensity of the scattered light is measured by a detector at 173o”.
- d) Smoluchowski equation --> components are missing!
Smoluchowski equation was presented and still exists in Part 2.3., Page 4, Line 141.
FINAL REMARKS
Overall, this manuscript is very much incremental, and the content is too little and too insignificant to publish. Thus, unfortunately, I DO NOT SUPPORT the publication of this manuscript. I hope the authors benefit from this report.
Author Response File: 
Author Response.docx
Reviewer 2 Report
This paper deals with the electrochemical performance of hybrid Zn coating on steel substrate in which ZnO and CuO nanoparticles were added. The content is of scientific interest and fit with the scope of the Journal. However, the presentation especially of the results section is not satisfactory and need to be implemented before the manuscript is suitable for publication.
In the title and also in the manuscript, the Authors cited the problem of biofouling. However, the results reported in the paper did not show any characterization about this corrosion issue. I suggest to better discuss in the title and in the introduction, in order to be coherent with the other parts of the paper.
Page 2 lines 45-51: Is it possible to more precisely group the cited references with the concept written? This would help the reader.
Page 4 par. 2.4 and 2.5: In the description of the procedure of electrodeposition, please add all the information to make reproducible the process, as the duration of the process, if a AC or DC current was applied and so on.
In chapter 3, in general the discussion of the results is poor. For example par. 3.1 and 3.2 reports the characterization of nanoparticles, but the Authors have not discussed the influence of this characterization on the coating performance.
In addition, figures should be improved, as Figure 3 in which a and b report micrographs in two different direction. I suggest to put the view of the coating above the substrate in both the micrographs.
Figure 7 reports the PDP curves after 25 days of immersion to chloride rich solution. These curves did not exhibit the passivation branch anymore. I suggest to add this information and the possible reasons for this behavior in comparison with the data reported in Figure 6 to enrich the discussion.
Please improve also the quality of Figure 8. The inlet is not clearly readable and invert A and B labels.
Finally, please read carefully all the paper since a lot of typos were found (page 5 lines 215-219: a paragraph from the journal guidelines is present within the paper text).
Author Response
This paper deals with the electrochemical performance of hybrid Zn coating on steel substrate in which ZnO and CuO nanoparticles were added. The content is of scientific interest and fit with the scope of the Journal. However, the presentation especially of the results section is not satisfactory and need to be implemented before the manuscript is suitable for publication.
In the title and also in the manuscript, the Authors cited the problem of biofouling. However, the results reported in the paper did not show any characterization about this corrosion issue. I suggest to better discuss in the title and in the introduction, in order to be coherent with the other parts of the paper.
The authors agree with the reviewer’s comment. The main aim of the investigations was to develop multilayer systems which could protect the low carbon steel simultaneously against corrosion and biofouling. According to some research data it could be expected that the availability of copper ions will protect the steel against this phenomenon. Аt this stage we just wanted to make sure that the method for obtaining of polymer-modified particles can be used to develop protective multilayer systems. However, our investigations are still at the beginning stage and we will proceed with more appropriate test methods. Having in mind the reviewer’s comment the title and some parts of the main text of the manuscript have been changed and corrected.
Page 2 lines 45-51: Is it possible to more precisely group the cited references with the concept written? This would help the reader.
The reviewer's comment is taken into consideration. The text has been changed and the cited references are more precisely grouped.
Page 4 par. 2.4 and 2.5: In the description of the procedure of electrodeposition, please add all the information to make reproducible the process, as the duration of the process, if a AC or DC current was applied and so on.
The reviewer's comment is taken into consideration. The text has been changed and the needed information is added.
In chapter 3, in general the discussion of the results is poor. For example par. 3.1 and 3.2 reports the characterization of nanoparticles, but the Authors have not discussed the influence of this characterization on the coating performance.
The authors agree with the reviewer’s comment. The text presented below has been added to the manuscript in Part 3.2:
“The main conclusion from the above experiments is that the nanoparticles in both suspensions are stabilized against aggregation (zeta-potential of the particles increase to about 50 mV due to the polyelectrolyte adsorption), which is of importance for obtaining of layers containing well dispersed oxide particles of low solubility at pH of the suspensions close to their isoelectric points.”
In addition, figures should be improved, as Figure 3 in which a and b report micrographs in two different direction. I suggest to put the view of the coating above the substrate in both the micrographs.
The reviewer's comment is taken into consideration. The view of the micrographs and the directions has been changed according to the recommendation.
Figure 7 reports the PDP curves after 25 days of immersion to chloride rich solution. These curves did not exhibit the passivation branch anymore. I suggest to add this information and the possible reasons for this behavior in comparison with the data reported in Figure 6 to enrich the discussion.
The reviewer's comment is taken into consideration. The text has been changed and the possible reasons have been discussed.
Please improve also the quality of Figure 8. The inlet is not clearly readable and invert A and B labels.
The reviewer's comment is taken into consideration. The quality of the figures including the inset is improved. The A and B labels have been inverted.
Finally, please read carefully all the paper since a lot of typos were found (page 5 lines 215-219: a paragraph from the journal guidelines is present within the paper text).
The reviewer's comment is taken into consideration. The text has been read and some corrections (marked in yellow) are included.
Author Response File: Author Response.docx
Reviewer 3 Report
please change font size in lines 294, 295
Fig. 8 lines 306 and 307 please correct description of ZnO line must be "ZnO" not "ZuO" (both cases).
Author Response
please change font size in lines 294, 295
The reviewer's comment is taken into consideration. The text has been checked for the font size of the letters and corrected.
Fig. 8 lines 306 and 307 please correct description of ZnO line must be "ZnO" not "ZuO" (both cases).
The reviewer's comment is taken into consideration. The text has been corrected.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The manuscript entitled "Hybrid zinc-based systems with improved corrosion resistance incorporating polymer-modified layers of ZnO or CuO particles" (MS#: coatings-1374763) is the revised version of a previous submission ("Hybrid Zinc-Based Coatings with Improved Protective Ability Against Localized Corrosion and Biofouling") I evaluated <2 weeks back.
In my previous report, I recommended the rejection of this manuscript without further review on the basis of extensive plagiarism, mismatch of the title/abstract and the content, lack of enough novelty, and inappropriate materials design (for the intended application). The authors submitted a revised version alongside a response letter with somewhat point-by-point replies. For practical reasons, I will first evaluate the replies of the authors, following the same order. Then, I will provide a few new comments and share my final disposition (under FINAL REMARKS).
1) ON MISMATCH OF SCOPE/TITLE AND CONTENT
There was absolutely no actual content in the manuscript directly demonstrating the biofouling effect. In the revised version, the authors no longer use the term biofouling in their title. However, all of those mentions remain in the manuscript. To be precise, the authors used this term with an extended mention one more time. Frankly, I got difficulty in understanding why the authors insist on such an apparent mistake. One reason might be their wish to comply with their funding/project: "Developing novel composite materials and their surface coatings for long-term anti-corrosion/biofouling application." But whatever the core reason behind it, I see a potential ethical issue here. And, I am firmly against such misleading practices.
2) ON COATING DESIGN NOVELTY & FUNCTIONALITY
The authors tried to explain why their proposed materials design is relevant and functional for biofouling control. Nevertheless, I am totally unconvinced as the intended functionality is speculative (biofouling control). In their response letter, the authors use the following sentences: "… the coating containing polymer-modified CuO particles is intentionally placed under the ordinary zinc layer aiming to obtain additional protective effect after the dissolution of zinc and its corrosion products (which have a barrier effect) in order to hinder the penetrating of bioagents to the steel substrate."
Again, the functional of the layer underneath zinc (polyethylenimine plus copper oxide nanoparticles). Under realistic conditions, such a polyelectrolyte-based coating formulation might serve as a weak point as being highly water-soluble. As a result, as I have implied before, this manuscript's central premise is speculative.
3) ON TEXT PLAGIARISM
In my previous report, I pointed out that 31% of this manuscript is unoriginal (under the default setting of iThenticate, when the author names, affiliations, and other generic texts, such as the references, are excluded. In defense, the authors claim that they "do not accept this remark since they believe, it should be borne in mind that certain terms, methods, electrodes, etc. cannot be replaced (or it is very difficult and sometimes inappropriate) by other expressions or phrases."
This defense is not quite acceptable. If some experimental sections have been described elsewhere, the authors should cite and then summarize in the current manuscript, which will sort out the plagiarism problem. However, it is crucial to note that the problem is not limited to what the authors mentioned. In contrast to what the authors implied, the plagiarism problem is beyond the experimental section. And, the authors are well aware of what they did as they replaced the entirely unoriginal paragraphs (i.e., fourth and fifth in the original manuscript). Nevertheless, as the authors did not touch the other unoriginal parts that I did not mention, the text-similarity index hits 23% in the current version. (This includes the copied experimental section parts and other texts, which are around 50%-50%, approximately.) Again, I am firmly against such practices.
4) ON THE WRITING QUALITY
The authors deleted the remnants of the manuscript template and did some corrections. The authors also corrected how the "Smoluchowski equation" reads in their manuscript. And, they highlighted this correction in their revised manuscript. (However, their response is not sensical as I did not imply that the equations is not missing. I meant that some of the components of the equation were missing, which is now fixed.)
P.S.: There are still several writing and formatting issues in the revised version.
FINAL REMARKS
Overall, this manuscript is still incremental, and its content is insufficient to make a journal article publication. Moreover, I have deep ethical concerns about the publication of this manuscript. (As explained above, the paper's overall structure is misleading, and the plagiarism problem persists.) Thus, I DO NOT SUPPORT the publication of this manuscript.
Author Response
The manuscript entitled "Hybrid zinc-based systems with improved corrosion resistance incorporating polymer-modified layers of ZnO or CuO particles" (MS#: coatings-1374763) is the revised version of a previous submission ("Hybrid Zinc-Based Coatings with Improved Protective Ability Against Localized Corrosion and Biofouling") I evaluated <2 weeks back.
In my previous report, I recommended the rejection of this manuscript without further review on the basis of extensive plagiarism, mismatch of the title/abstract and the content, lack of enough novelty, and inappropriate materials design (for the intended application). The authors submitted a revised version alongside a response letter with somewhat point-by-point replies. For practical reasons, I will first evaluate the replies of the authors, following the same order. Then, I will provide a few new comments and share my final disposition (under FINAL REMARKS).
Тhe authors do not accept that opinion (…“somewhat point-by-point replies???“), as they have answered all the remarks quite correctly – point-by-point.
1) ON MISMATCH OF SCOPE/TITLE AND CONTENT
There was absolutely no actual content in the manuscript directly demonstrating the biofouling effect. In the revised version, the authors no longer use the term biofouling in their title. However, all of those mentions remain in the manuscript. To be precise, the authors used this term with an extended mention one more time. Frankly, I got difficulty in understanding why the authors insist on such an apparent mistake. One reason might be their wish to comply with their funding/project: "Developing novel composite materials and their surface coatings for long-term anti-corrosion/biofouling application." But whatever the core reason behind it, I see a potential ethical issue here. And, I am firmly against such misleading practices.
It seems that the reviewer has not understood in detail (cannot or does not want to) our rationale for conducting these studies. Although it is clear to the authors that he will not change his position in any way to make it clear we will write it one more time - this is a preliminary study on the possibility of applying these particles with a view to future use against biofouling. Our text check found that we have used the word “biofouling” a total of 8 times in the text - 2 times on the first page (Abstract and Introduction), as well as once on the second and third pages, respectively. It appears again in the title of our project (Acknowledgements) and 3 times was included as a journal title in the References. This part of the comments and the reviewer's insistence exactly on that word makes us think that it is simply either a personal attitude towards us (negative) or a conflict of interest in this area.
2) ON COATING DESIGN NOVELTY & FUNCTIONALITY
The authors tried to explain why their proposed materials design is relevant and functional for biofouling control. Nevertheless, I am totally unconvinced as the intended functionality is speculative (biofouling control). In their response letter, the authors use the following sentences: "… the coating containing polymer-modified CuO particles is intentionally placed under the ordinary zinc layer aiming to obtain additional protective effect after the dissolution of zinc and its corrosion products (which have a barrier effect) in order to hinder the penetrating of bioagents to the steel substrate."
Again, the functional of the layer underneath zinc (polyethylenimine plus copper oxide nanoparticles). Under realistic conditions, such a polyelectrolyte-based coating formulation might serve as a weak point as being highly water-soluble. As a result, as I have implied before, this manuscript's central premise is speculative.
The authors have already answered this comment and do not accept it, as the experimental results show just the opposite. In this case it is a personal opinion of the reviewer, which has no practical justification at this time.
3) ON TEXT PLAGIARISM
In my previous report, I pointed out that 31% of this manuscript is unoriginal (under the default setting of iThenticate, when the author names, affiliations, and other generic texts, such as the references, are excluded. In defense, the authors claim that they "do not accept this remark since they believe, it should be borne in mind that certain terms, methods, electrodes, etc. cannot be replaced (or it is very difficult and sometimes inappropriate) by other expressions or phrases."
This defense is not quite acceptable. If some experimental sections have been described elsewhere, the authors should cite and then summarize in the current manuscript, which will sort out the plagiarism problem. However, it is crucial to note that the problem is not limited to what the authors mentioned. In contrast to what the authors implied, the plagiarism problem is beyond the experimental section. And, the authors are well aware of what they did as they replaced the entirely unoriginal paragraphs (i.e., fourth and fifth in the original manuscript). Nevertheless, as the authors did not touch the other unoriginal parts that I did not mention, the text-similarity index hits 23% in the current version. (This includes the copied experimental section parts and other texts, which are around 50%-50%, approximately.) Again, I am firmly against such practices.
The authors have checked the text for plagiarism with programs from the Internet (Duplichecker, for example), where the percentage of repeatability is about10%. Тhe authors will not comment on this topic again, as they do not see the point in it.
4) ON THE WRITING QUALITY
The authors deleted the remnants of the manuscript template and did some corrections. The authors also corrected how the "Smoluchowski equation" reads in their manuscript. And, they highlighted this correction in their revised manuscript. (However, their response is not sensical as I did not imply that the equations is not missing. I meant that some of the components of the equation were missing, which is now fixed.)
P.S.: There are still several writing and formatting issues in the revised version.
Apparently the reviewer again did not understand that these errors were not the authors', but occurred when transferring the text to the template, probably due to software problems.
FINAL REMARKS
Overall, this manuscript is still incremental, and its content is insufficient to make a journal article publication. Moreover, I have deep ethical concerns about the publication of this manuscript. (As explained above, the paper's overall structure is misleading, and the plagiarism problem persists.) Thus, I DO NOT SUPPORT the publication of this manuscript.
The authors will not comment on the reviewer's decision, but for them there is some doubt about his impartiality.
Author Response File: Author Response.docx
Reviewer 2 Report
Authors have implemented the manuscript following the reviewers' comments. The quality of the paper is significantly increased and now it can be published in the present form.
Author Response
Authors have implemented the manuscript following the reviewers' comments. The quality of the paper is significantly increased and now it can be published in the present form.
The authors are extremely and heartily grateful to the respected reviewer for the fairly assessing their efforts to improve the quality of the manuscript in order to meet the high requirements of the journal.
Author Response File: Author Response.docx
