Preparation and Corrosion Resistance of Superhydrophobic Coatings on 7005 Aluminum Alloy
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
The authors describe a method for the fabrication of a fluorine-free superhydrophobic coating possessing self-cleaning and anti-corrosion properties. The manuscript is not recommended for further consideration and publication.
1) The abstract is a stand-alone part of any article and as such, it must provide answers to four main questions. In particular, what is done, why it is done (the scientific motivation), how it is done and what are the main results (clearly pointing out how these results advance the field). At the moment, the abstract does not meet this requirement.
2) The Introduction section is written in a quite trivial way (explaining very scarcely the benefits of superhydrophobicity, then stating that most methods use harmful chemicals and/or are expensive, etc., and finally summarizing the main aspects of the presented research) and therefore, it does not bring any new scientific insights to the reader. In other words, it does not analyze competently the major problems in the particular field, based on short, but comprehensive analysis of the current state-of-the-art, and hence, fails to outline the scientific novelty (advancements) of the research under evaluation.
3) It must be mentioned that the use of stearic acid and SiO2 particles for the fabrication of superhydrophobic surfaces is not a new technique (examples include, but are not limited to - https://www.sciencedirect.com/science/article/pii/S0169433222002112 ; https://ieeexplore.ieee.org/document/9046592 ; https://www.mdpi.com/2079-6412/11/3/326 ). Thus, the manuscript under review does not provide solid evidences for scientific excellence and/or advance.
4) There are miscited literature sources in the Introduction. For instance, refs. 6-7-8-9 do not consider the fabrication of new anti-corrosion materials/coatings. Also, ref. 11 has nothing to do with the anti-icing properties of superhydrophobic surfaces, nor ref. 12.
5) Section 2.2 is described in a qualitative manner. In other words, there is no information about the quantity of used materials and rationale of why these quantities are selected. A skillful researcher will not be able to reproduce the findings. A short example: "First, a certain amount of SiO2 nanoparticles, stearic acid and alcohol were successively added to the beaker. The mixture was stirred in a magnetic mixer for several hours until completelydissolved. Next, the mixture was weighed and dissolvedin alcohol again."
6) "This is mainly because that the surface of the pure SiO2 nanoparticles contains a large number of hydroxyl groups with large surface energy, so it is easy to distribute in agglomeration state after modification." - this statement is not validated experimentally and it is not supported by any previously published scientific literature.
7) "improved micro- and nano-scale structures trapped enough air to prevent water from infiltrating the grooves, allowing dirt to be removed as the water droplets rolled." - it is not the air that ceases the liquid penetration into the surface protrusions. Please examine in detail the basics of superhydrophobicity - https://www.sciencedirect.com/science/article/pii/S0001868609001055
8) The FTIR and XPS spectra should be interpreted in light of the existing knowledge.
9) The anti-corrosion mechanisms of the as-prepared surface is not explained. If it is related only to the trapped air-driven inhibition of penetrating corrosive ions, then it does not add any new knowledge.
10) The conclusions' content repeats more or less that of the abstract, which is unacceptable.
Comments on the Quality of English Language
Moderate English editing required.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authors
Dear authors
The poor grammar of the article (numerous missing spaces between words - e.g. line 14 repared on the surface of semi-continuous cast7005aluminumalloy after different aging) throughout the entire article makes it difficult to read.
The poor grammar reflects badly on your scientific work and I am surprised that the editor sent such article for review.
I suggest that you write the article according to the grammar rules and to resubmit for publication.
Comments on the Quality of English Language
The poor grammar of the article (numerous missing spaces between words) throughout the entire article makes it difficult to read.
Author Response
Dear Reviewer:
Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Preparation and corrosion resistance of superhydrophobic coatings on 7005 aluminum alloy”. Those comments are all valuable and very helpful for revising and improving our paper. The main corrections in the paper and the responds to the reviewer’s comments are as flowing:
Response to Referee 2:
The poor grammar of the article (numerous missing spaces between words - e.g. line 14 repared on the surface of semi-continuous cast 7005 aluminum alloy after different aging) throughout the entire article makes it difficult to read. The poor grammar reflects badly on your scientific work and I am surprised that the editor sent such article for review.
I suggest that you write the article according to the grammar rules and to resubmit for publication.
Response: Thank you for pointing out the problem in manuscript. It is my first paper in this research. We submitted the paper in a little hurry. We are very sorry for the poor grammar of the paper. So we revised it many times and found a professional company to polish the paper.
Reviewer 3 Report
Comments and Suggestions for Authors
Dear authors, your work is interesting.
1. The research gap has been well described.
2. The purpose of the research was formulated correctly.
3. The research methodology is correct, despite the use of several very simple research methods. For example, abrasive wear test.
4. The work does not provide the proportions of materials constituting the coating. Is this due to patent restrictions?
5. When cutting the sample with a knife, what were the process conditions? How do we know that the samples were cut under the same conditions? it's about the pressure of the cutting blade on the sample, cutting speed, etc.
6. The most important part of the article verifying the quality of the coating is the corrosion tests.
In my opinion, the article is suitable for publication.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for Authors
The paper entitled: “Preparation and corrosion resistance of superhydrophobic coatings on 7005 aluminum alloy” was studied the corrosion resistance of 7005 aluminum alloy in NaCl by organic/inorganic hybrid coatings of stearic acid (STA) and silica (SiO2) are prepared on the surface of semi-continuous cast7005 aluminum alloy after different aging treatments (T6, RRA and FSA) by a simple two-step modification method (sol-gel). The surface morphology, surface roughness, chemical composition and wettability of the superhydrophobic coatings are characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and contact angles; measurements corrosion tests were determined by electrochemical methods, potentiodynamic polarization.
Few suggestions for possible improvement are:
-There are minor drafting errors in all text
-What is the composition of the on 7005 aluminum alloy?
-More details on the procedure for obtaining of organic/inorganic hybrid coatings (not clear to me)
-More details and comments from potentiodynamic polarization
-Electrochemical impedance spectroscopy (EIS) was not found in the corrosion resistance study,
In my opinion the paper: “Preparation and corrosion resistance of superhydrophobic coatings on 7005 aluminum alloy” after being revised it can be published in your journal.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for Authors
The authors have made an attempt to modify the manuscript and its content is indeed improved. However, this research still lacks to represent significant scientific novelty in order to be publishable in reputable journal.
1) The abstract has been rewritten, but nevertheless the answer of the question why the research is done and why it is necessary, what advancement it brings, is not provided.
2) The Introduction section still does not outline what is the scientific novelty of this study compared to the existing scientific literature. This is a huge shortcoming and if published that way, the paper will make very incremental advancement in the field and most probably will not be citable.
3) Section 2.1 and the Materials and methods section as a whole, still contains expression such as "for a period of time..." that does not bring any specific information on how exactly the experiments are performed, and most importantly - why?
4) Moreover, the authors provide some results from mechanical durability test, but there is no subsection in Materials and methods explaining how these tests are performed and why.
5) The interpretation related to the "air cushion lifting the pollutants" is absolutely incorrect and highly naive. If an expert reads this paper, he/she will acquire a very bad impression regarding the knowledge of authors in terms of wetting phenomena. In my first report i recommended a very detailed review article, where the basics of wetting and superhydrophobicity are explained quite well, but the authors ignored the suggestion and decided to skip the examination of this article - https://www.sciencedirect.com/science/article/abs/pii/S0001868609001055
6) A video file, supporting the snap shots in Figure 8, should be provided as a supplementary material.
7) Still, the performance of the as-developed superhydrophobic coating (both mechanical and anti-corrosion) is not compared to that of the existing analogues. So, it is unclear how the results advance the field.
8) Finally, it is the authors sole interest to write a really nice article containing ALL mandatory components of a research paper, otherwise, the published material will be ignored by the scientific community.
Comments on the Quality of English Language
The English language is ok.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authors
Dear Autors,
The properties of materials are determined by their structure. Given the microstructure, you can explain the chemical and mechanical properties you have measured.
Just describing the coating process and the measurements of the coating properties is usually not enough for a scientific article. It is necessary to correlate the microstructural characteristics with the properties achieved.
You mention nanoparticles and composite structure several times in the article. What is missing are microstructural analyses of the surface and cross-section of the layer (HRSEM or SEM FIB technique) to demonstrate such a structure.
To improve the article, I would advise the authors to perform an electron scanning microscope analysis and a microchemical analysis by SEM with a high enough resolution to observe the nanoparticles in the matrix and on the surface.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Round 3
Reviewer 1 Report
Comments and Suggestions for Authors
Although the scientific motivation behind this research is still not convincingly explained (in light of the current state-of-the-art), the authors have made great efforts to improve the manuscript's quality. Therefore, i think it can be published.
