Controllable Construction and Corrosion Resistance Mechanism of Durable Superhydrophobic Micro-Nano Structure on Aluminum Alloy Surface
Round 1
Reviewer 1 Report
The manuscript is fascinating. I have only a few comments.
Table 2 EIS parameters obtained from analog circuits
It is necessary to put an end after 2. (Table 2.) Figure captions also often lack punctuation marking.
14 (a) schematic diagram of the friction experiment
schematic Must be capitalized.
Reference style
The title of the cited article should be in italics. Year – in bold. In the text, reference numbers should be placed in square brackets [ ], and placed before the punctuation; for example [1], [1–3], or [1,3]. And the authors have a superscript [1–3]
The list of literary references also lacks the necessary points. Authors need to check everything carefully.
1. Author 1, A.B.; Author 2, C.D. Title of the article. Abbreviated Journal Name Year, Volume, page range.
Trdan U, Sano T, Klobčar D, et al. Improvement of corrosion resistance of AA2024-T3 using femtosecond laser peening without a protective and confining medium. Corrosion Science, 2018, 143: 46-55.vv
Use the MDPI style for this manuscript.
A few mistakes, such as below (check into the yellow).
Aluminum alloy corrosion resistance could be improved by micro-nanostructures on superhydrophobic surfaces, but inadequate mechanical stability remains a bottleneck concern in the sector. Herein, femtosecond laser rocessing and spray modification techniques are employed to fabricate "armor-style" micro-nanostructures on aluminum alloy surfaces. achieving controllable construction of durable superhydrophobic surfaces ware controllably constructed by this strategy.
Author Response
Dear Editor and Reviewers of the SUSTAINABILITY,
It is great thanks to you for the consideration of our manuscript “Controllable construction and corrosion resistance mechanism of durable superhydrophobic micro-nano structure on aluminum alloy surface” (Sustainability-04-2023-2401633), and for allowing us to revise our manuscript.
The suggestions of the editor and referees have been seriously considered and the manuscript has been further experimented, analyzed, and revised based on these comments. The revised manuscript, a copy of the revised version in which all revised contents have been marked red, and the point-by-point response to referees’ comments are resubmitted using your online submission.
Please let me know any decisions you have made on the manuscript.
Thanks again for your and the referees’ advice.
Yours Sincerely,
Dr. Peng Xu
College of Materials and Metallurgy,
Guizhou University, Guiyang, 550025, China,
- mail: [email protected].
Response to the editor and reviewers’ comments
About the questions and advice from Reviewer #1's comments:
The manuscript is fascinating. I have only a few comments.
Reply to Reviewer:
Thank you very much for your approval. We have revised the manuscript as required. Your valuable comments have indeed greatly improved the quality of the paper. Thanks again for your valuable comments.
Remark 1:
Table 2 EIS parameters obtained from analog circuits.
It is necessary to put an end after 2. (Table 2.) Figure captions also often lack punctuation marking.
Reply to Reviewer:
Thank you very much for your valuable comments. We made adjustments to Table 2 and added punctuation marks to the graph titles. Thanks again for your valuable comments.
Remark 2:
14 (a) schematic diagram of the friction experiment. Schematic Must be capitalized.
Reply to Reviewer:
Thank you very much for your valuable comments. We have made modifications to the text. Thanks again for your valuable comments.
Modification of Manuscript:
Fig. 14 (a) Schematic diagram of friction experiment
Remark 3:
Reference style
The title of the cited article should be in italics. Year – in bold. In the text, reference numbers should be placed in square brackets [ ], and placed before the punctuation; for example [1], [1–3], or [1,3]. And the authors have a superscript [1–3].
Reply to Reviewer:
Thank you very much for your valuable comments. We have made modifications to the reference style. Thanks again for your valuable comments.
Modification of Manuscript:
Currently, this material is utilized in a wide variety of applications including marine engineering, ship transportation, and rail transit systems, among others[1-3].
Remark 4:
The list of literary references also lacks the necessary points. Authors need to check everything carefully.
Author 1, A.B.; Author 2, C.D. Title of the article. Abbreviated Journal Name Year, Volume, page range.
Trdan U, Sano T, Klobčar D, et al. Improvement of corrosion resistance of AA2024-T3 using femtosecond laser peening without a protective and confining medium. Corrosion Science, 2018, 143: 46-55.
Reply to Reviewer:
Thank you very much for your valuable comments. We have made corresponding modifications to the references section. Thanks again for your valuable comments.
Modification of Manuscript:
Trdan U, Sano T, Klobčar D, et al. Improvement of corrosion resistance of AA2024-T3 using femtosecond laser peening without protective and confining medium. Corrosion Science, 2018, 143: 46-55.
Remark 5:
A few mistakes, such as below (check into the yellow).
Aluminum alloy corrosion resistance could be improved by micro-nanostructures on superhydrophobic surfaces, but inadequate mechanical stability remains a bottleneck concern in the sector. Herein, femtosecond laser rocessing and spray modification techniques are employed to fabricate "armor-style" micro-nanostructures on aluminum alloy surfaces. achieving controllable construction of durable superhydrophobic surfaces ware controllably constructed by this strategy.
Reply to Reviewer:
Thank you very much for your valuable comments. We have corrected errors in the text. Thanks again for your valuable comments.
Modification of Manuscript:
Aluminum alloy corrosion resistance could be improved by micro-nanostructures on superhydrophobic surfaces, but inadequate mechanical stability remains a bottleneck concern in the sector. Herein, femtosecond laser processing and spray modification techniques are employed to fabricate "armor-style" micro-nanostructures on aluminum alloy surfaces. achieving controllable construction of durable superhydrophobic surfaces were controllably constructed by this strategy.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript “Controllable construction and corrosion resistance mechanism of durable superhydrophobic micro-nano structure on aluminum alloy surface” is recommended for publication. However, a number of corrections need to be made before publication.
1. The introduction very well describes the previous research on the deposition of hydrophobic surfaces, as well as laser surface treatment. However, nothing is said in the introduction about the experience of using nanosilica. Please fill in the missing information.
2. Line 99. Please indicate the manufacturer of the aluminum alloy.
3. Line 99. Please specify the composition of the aluminum alloy. Is it pure aluminum? Does it contain impurities of other metals?
4. Lines 103 - 106. On what basis were the laser processing conditions chosen? Have these conditions been mentioned earlier in the literature?
5. Lines 103 - 106. What area of aluminum alloy can be treated with a laser? Are there any restrictions related to the design of the machine?
6. Continuation to the previous question. In real life, aluminum parts are usually large. In this regard, is it possible to use the method of processing aluminum alloy developed by you in industrial conditions?
7. Lines 129-133. What is the solution spray time?
8. Lines 132-133. Is drying used after application of the silica solution? What were the drying conditions?
9. Lines 129-133. Please indicate that you varied the number of applied layers. It is important.
10. Lines 129-133. Can the word "solution" be used here? Maybe it's more correct to write "suspension"?
11. Lines 153-156. It would be good to supplement the adhesion test with a study of mechanical strength. What force must be applied to tear off the strip from the clean and machined alloy?
12. Figure 7 would be nice to complete with a comparison with untreated samples.
Author Response
Dear Editor and Reviewers of the SUSTAINABILITY,
It is great thanks to you for the consideration of our manuscript “Controllable construction and corrosion resistance mechanism of durable superhydrophobic micro-nano structure on aluminum alloy surface” (Sustainability-04-2023-2401633), and for allowing us to revise our manuscript.
The suggestions of the editor and referees have been seriously considered and the manuscript has been further experimented, analyzed, and revised based on these comments. The revised manuscript, a copy of the revised version in which all revised contents have been marked red, and the point-by-point response to referees’ comments are resubmitted using your online submission.
Please let me know any decisions you have made on the manuscript.
Thanks again for your and the referees’ advice.
Yours Sincerely,
Dr. Peng Xu
College of Materials and Metallurgy,
Guizhou University, Guiyang, 550025, China,
- mail: [email protected].
About the questions and advice from Reviewer #2's comments:
The manuscript “Controllable construction and corrosion resistance mechanism of durable superhydrophobic micro-nano structure on aluminum alloy surface” is recommended for publication. However, a number of corrections need to be made before publication.
Reply to Reviewer:
Thank you very much for your valuable comments. We have revised the manuscript according to your requirements and added some new content. Your valuable comments have indeed greatly improved the quality of the paper. Thank you again for your valuable comment.
Remark 1:
The introduction very well describes the previous research on the deposition of hydrophobic surfaces, as well as laser surface treatment. However, nothing is said in the introduction about the experience of using nanosilica. Please fill in the missing information.
Reply to Reviewer:
Thank you very much for your valuable comments. We have added references to the use of silica nanoparticles in the introduction. Thanks again for your valuable comments.
Modification of Manuscript:
Yu et al.[19] successfully fabricated a superhydrophobic surface by spray-coating aluminum with silica nanoparticles. Meanwhile, the prepared superhydrophobic material has exhibited outstanding self-cleaning performance, durability, and stability under harsh environmental conditions.
[19] Yu X, Liu X, Shi X, et al. SiO2 nanoparticle-based superhydrophobic spray and multi-functional surfaces by a facile and scalable method. Ceramics International, 2019, 45(12): 15741-15744.
Remark 2-3:
Line 99. Please indicate the manufacturer of the aluminum alloy.
Line 99. Please specify the composition of the aluminum alloy. Is it pure aluminum? Does it contain impurities of other metals?
Reply to Reviewer:
Thank you very much for your valuable comments. We have supplemented information on the aluminum alloy. Thanks again for your valuable comments.
Modification of Manuscript:
Aluminum alloy (7075 aluminum alloy, Guiqian Aluminum Co., Ltd. Other elements are Si0.4, Fe0.5, Cu1.2-2.0, Mn0.3, Mg2.1-2.9, Cr0.18-0.28, Zn5.1-6.1, Ti0.2.)
Remark 4-6:
Lines 103 - 106. On what basis were the laser processing conditions chosen? Have these conditions been mentioned earlier in the literature?
Lines 103 - 106. What area of aluminum alloy can be treated with a laser? Are there any restrictions related to the design of the machine?
Continuation to the previous question. In real life, aluminum parts are usually large. In this regard, is it possible to use the method of processing aluminum alloy developed by you in industrial conditions?
Reply to Reviewer:
Thank you very much for your valuable comments. We have added a reference for selecting laser processing conditions in the text. Furthermore, the surface of the aluminum alloy can be subjected to laser processing after being treated with sandpaper. The processing method developed for industrial conditions could be employed for processing the aluminum alloy. Thanks again for your valuable comments.
Remark 7:
Lines 129-133. What is the solution spray time?
Reply to Reviewer:
Thank you very much for your valuable comments. We have made modifications to the text. Thanks again for your valuable comments.
Modification of Manuscript:
Finally, the suspension is applied onto the aluminum surface using a spray gun, followed by natural drying under room temperature, achieving a superhydrophobic effect. The solution is sprayed with a pressure of 0.8 MPa, and the nozzle distance from the sample surface is 10 mm.
Remark 8:
Lines 132-133. Is drying used after application of the silica solution? What were the drying conditions?
Reply to Reviewer:
Thank you very much for your valuable comments. We have provided additional details to the experimental description. Thanks again for your valuable comments.
Modification of Manuscript:
Finally, the suspension is applied onto the aluminum surface using a spray gun, followed by natural drying under room temperature, achieving a superhydrophobic effect.
Remark 9:
Lines 129-133. Can the word "solution" be used here? Maybe it's more correct to write "suspension"?
Reply to Reviewer:
Thank you very much for your valuable comments. The use of certain words here is inappropriate, we have made modifications to the text. Thanks again for your valuable comments.
Modification of Manuscript:
Finally, the suspension is applied onto the aluminum surface using a spray gun, followed by natural drying under room temperature, achieving a superhydrophobic effect.
Remark 10:
Lines 153-156. It would be good to supplement the adhesion test with a study of mechanical strength. What force must be applied to tear off the strip from the clean and machined alloy?
Reply to Reviewer:
Thank you very much for your valuable comments. Due to the extremely small size of the nanoscale silicon dioxide particles distributed throughout the armor-style structure, we cannot accurately measure the force required for attachment. However, through adhesive tape experiments, we have demonstrated that the superhydrophobic surface remains intact even after repeated adhesion tests, indicating a high level of stability in its adherence. Thanks again for your valuable comments.
Remark 11:
Figure 7 would be nice to complete with a comparison with untreated samples.
Reply to Reviewer:
Thank you very much for your valuable comments. In the experiment related to surface wettability, we have included comparative explanations between the unprocessed samples and their counterparts. Thanks again for your valuable comments.
Modification of Manuscript:
In the case of unprocessed samples, upon immersion in solution, no air layer is formed and upon removal from the solution, the surface cannot maintain dryness.
Author Response File: Author Response.docx
Reviewer 3 Report
The authors had utilized femtosecond laser technology to create a superhydrophobic layer on an aluminum alloy surface to serve as an anti-corrosion layer. The article is well-written, but some areas can be improved. Some minor suggestions from the reviewer are:
.
2. Please add the information regarding the wettability measurement method.
3. Figures 5 (a) and (b) are not SEM images. Please correct the caption and separate Figures 5 (a) and (b) from (c) and (d) if necessary.
4. Is there any correlation between the superhydrophobicity to the anticorrosion properties of the layer? Or are the two just coincidentally happening without any causation? please mention it.
Moderate editing of English language
Author Response
Dear Editor and Reviewers of the SUSTAINABILITY,
It is great thanks to you for the consideration of our manuscript “Controllable construction and corrosion resistance mechanism of durable superhydrophobic micro-nano structure on aluminum alloy surface” (Sustainability-04-2023-2401633), and for allowing us to revise our manuscript.
The suggestions of the editor and referees have been seriously considered and the manuscript has been further experimented, analyzed, and revised based on these comments. The revised manuscript, a copy of the revised version in which all revised contents have been marked red, and the point-by-point response to referees’ comments are resubmitted using your online submission.
Please let me know any decisions you have made on the manuscript.
Thanks again for your and the referees’ advice.
Yours Sincerely,
Dr. Peng Xu
College of Materials and Metallurgy,
Guizhou University, Guiyang, 550025, China,
- mail: [email protected].
About the questions and advice from Reviewer #3's comments:
The authors had utilized femtosecond laser technology to create a superhydrophobic layer on an aluminum alloy surface to serve as an anti-corrosion layer. The article is well-written, but some areas can be improved. Some minor suggestions from the reviewer are.
Reply to Reviewer:
Thank you very much for your valuable comments. Thank you for your approval and we have revised the manuscript as required. Your valuable comments have indeed greatly improved the quality of the paper. Thanks again for your valuable comments.
Remark 1:
Please add the information regarding the wettability measurement method.
Reply to Reviewer:
Thank you very much for your valuable comments. We have added information about the method used for measuring wettability. Thanks again for your valuable comments.
Modification of Manuscript:
To determine the CA and SA, an optical CA measurement system (JC2000D1, China) was employed to measure a 10 μL water droplet's CA and SA, with three measurements of each different position taken.
Remark 2:
Figures 5 (a) and (b) are not SEM images. Please correct the caption and separate Figures 5 (a) and (b) from (c) and (d) if necessary.
Reply to Reviewer:
Thank you very much for your valuable comments. We have corrected the erroneous description. Moreover, we have added punctuation marks to the legend for clarity. Thanks again for your valuable comments.
Modification of Manuscript:
Fig. 5 (a-b) Three-dimensional surface topography contour map, (c-d) SEM images of surface morphology after femtosecond laser treatment
Remark 3:
Is there any correlation between the superhydrophobicity to the anticorrosion properties of the layer? Or are the two just coincidentally happening without any causation? please mention it.
Reply to Reviewer:
Thank you very much for your valuable comments. There is a correlation between superhydrophobicity and anticorrosive properties, we have explained this relationship in the text. Thanks again for your valuable comments.
Modification of Manuscript:
Due to the superhydrophobic character of the specimen's surface, it exhibits a Cassie state of wetting. As is well known, "gas valleys" will be formed in the micro-nano peak structure under the Cassie state. The presence of "gas valleys" could obstruct the contact of corrosive ions with the substrate surface, such as Cl-, thereby significantly improving the corrosion resistance.
Author Response File: Author Response.docx
Reviewer 4 Report
The authors presented studies proving that modifying the surface of an aluminium alloy by femtosecond laser processing and nano-silica spray technique results in more favourable superhydrophobic properties and an increase in corrosion resistance.
The presented issue is interesting and may find practical application in the future, however, I believe that in less corrosive conditions.
I have the following comments and remarks.
It is known that aluminium alloys in typical weather conditions are protected by a passive native Al2O3 layer. The authors did not mention anything about this, and it undoubtedly affects the corrosion resistance of aluminium alloys. Fig. 9a shows that this layer is present for pure aluminium but not for the two modified samples. How to explain it? What effect does laser treatment have on this layer? What is the nature of the surface after laser treatment? Do the properties of the laser-treated surface change with exposure time in the air over several days as the native passive layer is formed on the sandpaper-cleaned surface? Please discuss it. At the end of the Introduction, please clearly indicate the novelty of the article, what is the originality of the presented research, and what is the authors' new idea.
There are many minor errors in the manuscript:
1. In line 33, in the introduction we don't mention a specific aluminium alloy "Aluminum alloy (7075 aluminum alloy) is ...", we do it in the experimental part, for example in line 99 (and it's not there), so in line 33 it should be " Aluminum alloys are ...".
2. line 57, "silane" should be deleted.
3. line 75, "stability" should be deleted.
4. lines 99-101, the sentence "Before processing, the surface was smoothed with 2000# sandpaper, and hydrophobic nano silica was purchased from Maclean Chemical Co., LTD" should be reworded, e.g. to two sentences, because it currently combines two different unrelated activities.
5. lines 108-109, the sentence "The prepared superhydrophobic coating was sectioned into a cubic shape with dimensions of 10mm x 10mm x 10mm." is incomprehensible, coating was sectioned? Is it really or aluminium substrate?
6. from line 124 onwards, the authors use the imperative mood (e.g. "immerse", "use", "let it dry") instead of the passive voice.
7. two types of laser surface modification are shown in Fig. 1, but they are not mentioned anywhere in the text. This needs to be supplemented.
8. line 141, what means "Calculated by determining the CA between ...", this expression is incomprehensible, please reword.
9. line 147 onwards: all equations should be numbered sequentially, the phrase "please use" is not appropriate here, reword it accordingly.
10. line 154, was the tape pressed to the surface or not, and with what, finger? This needs to be described in more detail.
11. The description of Figure 3 is too poor, which graph applies to which surfaces, what do the symbols A11, A12 and A13 mean?
12. There are no commas in the caption of Fig. 4, 5, which makes it difficult to assign descriptions to photos, no scale in the photos.
13. Fig. 6a, the description of the horizontal axis as "Spraying time" is incorrect and misleading, it needs to be changed.
14. lines 195-196, why do you need to apply the spray 4 times, any explanation?
15. line 211, remove the dot.
16. Fig. 7 and 8, why show photos for two samples, better for one, but with larger photos.
17. line 249, should be "potential" instead of "voltage".
18. line 253, remove the word "significantly," the figure shows that the differences are small (corrosion current density).
19. Fig. 7c should be moved to Fig. 8. This is more logical.
19. Table 1, correct "Bc" to "βc".
20. Table 2, correct "F cm2" to "F cm -2" (minus is missing).
21. lines 372-373, the sentence "The phase of the sample surface remained essentially unaltered after femtosecond laser processing, as shown by phase and phase." is incomprehensible.
22. line 432, should be "References".
Generally, the English language of the manuscript requires proofreading by a native speaker.
Some of the more important errors that hinder the understanding of the manuscript I have pointed out above.
Author Response
Dear Editor and Reviewers of the SUSTAINABILITY,
It is great thanks to you for the consideration of our manuscript “Controllable construction and corrosion resistance mechanism of durable superhydrophobic micro-nano structure on aluminum alloy surface” (Sustainability-04-2023-2401633), and for allowing us to revise our manuscript.
The suggestions of the editor and referees have been seriously considered and the manuscript has been further experimented, analyzed, and revised based on these comments. The revised manuscript, a copy of the revised version in which all revised contents have been marked red, and the point-by-point response to referees’ comments are resubmitted using your online submission.
Please let me know any decisions you have made on the manuscript.
Thanks again for your and the referees’ advice.
Yours Sincerely,
Dr. Peng Xu
College of Materials and Metallurgy,
Guizhou University, Guiyang, 550025, China,
- mail: [email protected].
About the questions and advice from Reviewer #4's comments:
The authors presented studies proving that modifying the surface of an aluminium alloy by femtosecond laser processing and nano-silica spray technique results in more favourable superhydrophobic properties and an increase in corrosion resistance.
The presented issue is interesting and may find practical application in the future, however, I believe that in less corrosive conditions.
I have the following comments and remarks.
It is known that aluminium alloys in typical weather conditions are protected by a passive native Al2O3 layer. The authors did not mention anything about this, and it undoubtedly affects the corrosion resistance of aluminium alloys. Fig. 9a shows that this layer is present for pure aluminium but not for the two modified samples. How to explain it? What effect does laser treatment have on this layer? What is the nature of the surface after laser treatment? Do the properties of the laser-treated surface change with exposure time in the air over several days as the native passive layer is formed on the sandpaper-cleaned surface? Please discuss it. At the end of the Introduction, please clearly indicate the novelty of the article, what is the originality of the presented research, and what is the authors' new idea.
Reply to Reviewer:
Sure, a protective layer of aluminum oxide (Al2O3) is known to form on the surface of pure aluminum. However, our study primarily focuses on the impact of superhydrophobic coatings on the corrosion resistance of pure aluminum. As previously mentioned, a Cassie-state superhydrophobic surface effectively isolates corrosive ions from direct contact with the surface, thus significantly improving resistance to corrosion. Therefore, the Al2O3 layer present on the surface does not impact the corrosion resistance of the superhydrophobic coating, as it does not come into contact with the solution. This is why we did not mention it in the article. Femtosecond laser processing is achieved by using a laser to ablate the surface of the material, resulting in oxidation of the surface as shown in the accompanying image.
To assess whether or not surface characteristics of laser-treated surfaces changed over time when exposed to air, we conducted an additional experiment as shown in the accompanying image. After being subjected to femtosecond laser ablation, the surface displayed hydrophilic properties. We left the treated surface undisturbed in ambient air for 10 days and found that it still retained its hydrophilic state. This indicates that the surface properties do not change over time.
Remark 1:
In line 33, in the introduction we don't mention a specific aluminium alloy "Aluminum alloy (7075 aluminum alloy) is ...", we do it in the experimental part, for example in line 99 (and it's not there), so in line 33 it should be " Aluminum alloys are ...".
Reply to Reviewer:
Thank you very much for your valuable comments. We have made modifications to the text. Thanks again for your valuable comments.
Modification of Manuscript:
Aluminum alloy is known for its exceptional lightweight properties, high strength-to-weight ratio, and low overall density.
Remark 2:
line 57, "silane" should be deleted.
Reply to Reviewer:
Thank you very much for your valuable comments. We have corrected errors in the text. Thanks again for your valuable comments.
Remark 3:
line 75, "stability" should be deleted.
Reply to Reviewer:
Thank you very much for your valuable comments. We have corrected errors in the text. Thanks again for your valuable comments.
Remark 4:
lines 99-101, the sentence "Before processing, the surface was smoothed with 2000# sandpaper, and hydrophobic nano silica was purchased from Maclean Chemical Co., LTD" should be reworded, e.g. to two sentences, because it currently combines two different unrelated activities.
Reply to Reviewer:
Thank you very much for your valuable comments. We have made modifications to the text. Thanks again for your valuable comments.
Modification of Manuscript:
before processing, the surface was smoothed with 2000# sandpaper. The hydrophobic nano-silica was purchased from Maclean Chemical Co., LTD. The hydrophobic nano-silica was sprayed four times during the experiment.
Remark 5:
lines 108-109, the sentence "The prepared superhydrophobic coating was sectioned into a cubic shape with dimensions of 10mm x 10mm x 10mm." is incomprehensible, coating was sectioned? Is it really or aluminium substrate?
Reply to Reviewer:
Thank you very much for your valuable comments. We have made modifications to the text. Thanks again for your valuable comments.
Modification of Manuscript:
The prepared sample was sectioned into a cubic shape with dimensions of 10mm x 10mm x 10mm.
Remark 6:
from line 124 onwards, the authors use the imperative mood (e.g. "immerse", "use", "let it dry") instead of the passive voice.
Reply to Reviewer:
Thank you very much for your valuable comments. I apologize for using an incorrect tone. We have made the necessary modifications to the text description. Thanks again for your valuable comments.
Modification of Manuscript:
Before the spraying operation, the sample (A cube with a side length of 10mm) treated with a femtosecond laser is immersed in alcohol and subjected to ultrasonic treatment for 20 minutes. Then, it is rinsed with deionized water followed by being dried at room temperature. A homogeneous solution is obtained by dispersing hydrophobic SiO2 nanoparticles (15~20 nm, 1.2 g) in 50 ml of ethanol and stirring it at 600 rpm for 2 hours, followed by a 30-minute ultrasonic treatment. Finally, the suspension is applied onto the aluminum surface using a spray gun, followed by natural drying under room temperature, achieving a superhydrophobic effect[29-31]. The solution is sprayed with a pressure of 0.8 MPa, and the nozzle distance from the sample surface is 10 mm.
Remark 7:
two types of laser surface modification are shown in Fig. 1, but they are not mentioned anywhere in the text. This needs to be supplemented.
Reply to Reviewer:
Thank you very much for your valuable comments. We have included additional descriptions for both types of samples in the following text. Thanks again for your valuable comments.
Remark 8:
line 141, what means "Calculated by determining the CA between ...", this expression is incomprehensible, please reword.
Reply to Reviewer:
Thank you very much for your valuable comments. We have modified the text description to allow for better comprehension. Thanks again for your valuable comments.
Modification of Manuscript:
By measuring CA in solutions with different pH values (pH=1~14), the chemical stability of superhydrophobic surfaces can be determined.
Remark 9:
line 147 onwards: all equations should be numbered sequentially, the phrase "please use" is not appropriate here, reword it accordingly.
Reply to Reviewer:
Thank you very much for your valuable comments. We have modified the text description to allow for better comprehension. Thanks again for your valuable comments.
Modification of Manuscript:
To determine the average jet velocity v, use the following formula for calculation
Remark 10:
line 154, was the tape pressed to the surface or not, and with what, finger? This needs to be described in more detail.
Reply to Reviewer:
Thank you very much for your valuable comments. We have supplemented the text with additional details to provide a more comprehensive description. Thanks again for your valuable comments.
Modification of Manuscript:
During each experiment, the central position of a piece of tape has adhered to the superhydrophobic surface, the two ends of the tape are then pulled down with force using fingers so that the tape is tightly attached to the superhydrophobic surface, which was then quickly pulled up.
Remark 11:
The description of Figure 3 is too poor, which graph applies to which surfaces, what do the symbols A11, A12 and A13 mean?
Reply to Reviewer:
Thank you very much for your valuable comments. We apologize for any unclear descriptions in our text. We have made modifications to the text to provide a more detailed account. Thanks again for your valuable comments.
Modification of Manuscript:
The XRD patterns for the substrate and two "armor-style" structures are shown in Fig (3). A11 and A12 correspond to the XRD spectra of the surfaces of samples with block and triangular structures, while A13 represents the XRD spectrum of the substrate surface. By comparing these three lines, it can be seen that the surface phases of the samples before and after femtosecond laser treatment remain consistent, mainly composed of α phase and η phase.
Remark 12:
There are no commas in the caption of Fig. 4, 5, which makes it difficult to assign descriptions to photos, no scale in the photos.
Reply to Reviewer:
Thank you very much for your valuable comments. We have made revisions to both the image and its corresponding description. Thanks again for your valuable comments.
Modification of Manuscript:
Fig. 4 (a) SEM image of block structure surface, (b-c) SEM image of triangular structure surface, (d) EDS spectra of block structure surface, (e) EDS spectra of triangular structure surface, (f) EDS spectra of the deeper triangular structure
Remark 13:
Fig. 6a, the description of the horizontal axis as "Spraying time" is incorrect and misleading, it needs to be changed.
Reply to Reviewer:
Thank you very much for your valuable comments. We have revised incorrect descriptions in our picture. Thanks again for your valuable comments.
Modification of Manuscript:
Remark 14:
lines 195-196, why do you need to apply the spray 4 times, any explanation?
Reply to Reviewer:
Thank you very much for your valuable comments. As the superhydrophobic performance no longer changes after four spray times, we have selected four as the optimal number of coatings. Thanks again for your valuable comments.
Remark 15:
line 211, remove the dot.
Reply to Reviewer:
Thank you very much for your valuable comments. We have made changes to the text Thanks again for your valuable comments.
Remark 16:
Fig. 7 and 8, why show photos for two samples, better for one, but with larger photos.
Reply to Reviewer:
Thank you very much for your valuable comments. We have made modifications to the image. Thanks again for your valuable comments.
Modification of Manuscript:
Remark 17:
line 249, should be "potential" instead of "voltage".
Reply to Reviewer:
Thank you very much for your valuable comments. We have made changes to the text Thanks again for your valuable comments.
Remark 18:
line 253, remove the word "significantly," the figure shows that the differences are small (corrosion current density).
Reply to Reviewer:
Thank you very much for your valuable comments. We have made modifications to the text. Thanks again for your valuable comments.
Remark 19:
Fig. 7c should be moved to Fig. 8. This is more logical.
Reply to Reviewer:
Thank you very much for your valuable comments. We have made the necessary modifications to the image. Thanks again for your valuable comments.
Modification of Manuscript:
Remark 20:
Table 1, correct "Bc" to "βc".
Reply to Reviewer:
Thank you very much for your valuable comments. We have made the proper modifications to the text description. Thanks again for your valuable comments.
Remark 21:
Table 2, correct "F cm2" to "F cm -2" (minus is missing).
Reply to Reviewer:
Thank you very much for your valuable comments. We have corrected errors in our text. Thanks again for your valuable comments.
Remark 22:
lines 372-373, the sentence "The phase of the sample surface remained essentially unaltered after femtosecond laser processing, as shown by phase and phase." is incomprehensible.
Reply to Reviewer:
Thank you very much for your valuable comments. We have modified the sentence to enhance understanding. Thanks again for your valuable comments.
Modification of Manuscript:
The phase of the sample surface remained essentially unaltered after femtosecond laser processing, it appears as α and η phase.
Remark 23:
line 432, should be "References".
Reply to Reviewer:
Thank you very much for your valuable comments. We have made corrections to the text. Thanks again for your valuable comments.
Author Response File: Author Response.docx
Round 2
Reviewer 4 Report
The authors revised the manuscript as recommended by the reviewers, including my comments, and the manuscript benefited from it.
I think the following bugs still need to be fixed:
1. Fig. 6(a) description of the horizontal axis, instead of "Spraying times" it is better to write "Number of spraying"
2. Fig. 12(b), "PH" should be "pH"
3. Fig. 14(b), the unit is missing at the "Abrasion time" axis
With these additions, it seems to me that the manuscript can be published.
I think minor adjustments are needed.
Author Response
Dear Editor and Reviewers of the SUSTAINABILITY,
It is great thanks to you for the consideration of our manuscript “Controllable construction and corrosion resistance mechanism of durable superhydrophobic micro-nano structure on aluminum alloy surface” (Sustainability-04-2023-2401633), and for allowing us to revise our manuscript.
The suggestions of the editor and referees have been seriously considered and the manuscript has been further experimented, analyzed, and revised based on these comments. The revised manuscript, a copy of the revised version in which all revised contents have been marked red, and the point-by-point response to referees’ comments are resubmitted using your online submission.
Please let me know any decisions you have made on the manuscript.
Thanks again for your and the referees’ advice.
Yours Sincerely,
Dr. Peng Xu
College of Materials and Metallurgy,
Guizhou University, Guiyang, 550025, China,
- mail: [email protected].
About the questions and advice from Reviewer #4's comments:
The authors revised the manuscript as recommended by the reviewers, including my comments, and the manuscript benefited from it.
I think the following bugs still need to be fixed.
Reply to Reviewer:
Thank you very much for your approval. We have revised the manuscript as required. Your valuable comments have indeed greatly improved the quality of the paper. Thanks again for your valuable comments.
Remark 1:
Fig. 6(a) description of the horizontal axis, instead of "Spraying times" it is better to write "Number of spraying"
Reply to Reviewer:
Thank you very much for your valuable comments. We have already made modifications to the description of the image's horizontal axis. Thanks again for your valuable comments.
Modification of Manuscript:
Remark 2:
Fig. 12(b), "PH" should be "pH"
Reply to Reviewer:
Thank you very much for your valuable comments. We have already made modifications to the text in the image. Thanks again for your valuable comments.
Modification of Manuscript:
Remark 3:
Fig. 14(b), the unit is missing at the "Abrasion time" axis
Reply to Reviewer:
Thank you very much for your valuable comments. We have already made modifications to the text in the image. Thanks again for your valuable comments.
Modification of Manuscript:
Author Response File: Author Response.docx
