Capsaicin-Modified Fluorosilicone Based Acrylate Coating for Marine Anti-Biofouling

Round 1

Reviewer 1 Report

1. The authors should explain the novelty of the work with more details.
2. The grammatical and typo errors should be revised.
3. Mention some of the surface factors affecting the strength of adhesion in the 3.2. Mechanical properties section.
4. What was the surface roughness of glass and steel substrate used for adhesion. Because surface roughness plays an important role in adhesion.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

In this article, the authors demonstrated a marine antifouling coating, which was prepared from a polymer network modified on HMBA (N-(4-hydroxy-3-methoxybenzyl)-acrylamide) as a capsaicin analogy. The coating was stable on water for a month and remained antibacterial and antialgal properties for 3 weeks. The article is suitable to publish to Coating, however, it has some inadequate descriptions, especially experimental sections, and several figures are hard to see. I recommend the publication of the paper after a major revision. I would like to suggest the following modifications be made as necessary.  

1. The authors should show a more suitable reference than reference 9 [Polymer 2017, 114, 113-121].
   The authors described on page 2 in lines 46-48, ”Its excellent antifouling properties and remarkably low environmental toxicity have been extensively studied since the first report on capsaicin-containing antifouling coatings in 1995 [9].”, however, the reference 9 [Polymer 2017, 114, 113-121] was published in 2017. I could not find any references published in 1995 from reference 9. In addition, reference 9 reported mainly lignin, it is not a suitable reference for the author's claims, even if capsaicin is a derivative of lignin.
   
2. The authors should describe the materials, such as liquid LB media and PBS, used for antibacterial assays in the Experimental section. The authors should describe the details of SEM and EDS analysis in the Experimental section.
   
   
3. It was described in the Experimental section that the monomers were mixed with AIBN at 75 degrees, however, the temperature was shown at 70 degrees in Figure 1. Which is correct?
   
   
4. The authors should show J-coupling and integrations of protons corresponding to each proton in 1H-NMR of HMBA.
5. The authors should explain AWS on page 7 in line 235.
6. It is hard to see the error bars in Figures 3A and 4G, H.
7. It is hard to see the gradient getting blacker toward the outside in Figure 4G, H.
8. The compound names should be listed alongside the chemical structures in Figure 1.
9. The authors should show 1H-NMR of PRE-0 to compare with PRE-10, 20, and 30 in Figure 2C.
10. The authors should show the GPC results of PRE-0. I think that Figure 2E is not necessary to show. It means that it is enough to show the results as Figure 2F.
11. The authors should explain WCA and DCA in Figure 3B, D.
12. The authors should describe which sample was used in SEM and EDS analyses in Figure 3E.
13. As I am color blind, it is difficult for me to recognize the colors of methacryloxypropyl (trimethylsiloxy) silane and triisocyanate in Figure 1. There are same problems in Figures 2C, D, E F, 3A, B, C, D, and 4H. For instance, it is difficult for me to recognize the red and green (?) vertical axes in Figure 2B. I would like to recommend changing the shape of each chemical compound in Figure 1 and changing the colors in all Figures.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The paper show novelty research and the data are all well exhibited.

I have 1 comment: GFE in Figure 3A stands for what? and please put PDMS in the list of Materials (section 2.1).

Author Response

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Round 2

Reviewer 2 Report

The editor should check that the authors have responded to the reviewer's comments. It shouldn't be the editor's work to forward a reviewer a manuscript.

I cited my previous comments as italic, and strikethrough ones have been revised.

strikethrough

 

1. The authors should show a more suitable reference than reference 9 [Polymer 2017, 114, 113-121].
   The authors described on page 2 in lines 46-48, ”Its excellent antifouling properties and remarkably low environmental toxicity have been extensively studied since the first report on capsaicin-containing antifouling coatings in 1995 [9].”, however, the reference 9 [Polymer 2017, 114, 113-121] was published in 2017. I could not find any references published in 1995 from reference 9. In addition, reference 9 reported mainly lignin, it is not a suitable reference for the author's claims, even if capsaicin is a derivative of lignin.
   
   The authors added reference 13, however, there is no refernce published in 1995 either. 
   
   
2. The authors should describe the materials, such as liquid LB media and PBS, used for antibacterial assays in the Experimental section. The authors should describe the details of SEM and EDS analysis in the Experimental section.
   
   The authors responed that SEM and EDS details have been added, howevwe, I could not find them in the revied manscirpit.
   
   
3. It was described in the Experimental section that the monomers were mixed with AIBN at 75 degrees, however, the temperature was shown at 70 degrees in Figure 1. Which is correct?
   
   
4. The authors should show J-coupling and integrations of protons corresponding to each proton in 1H-NMR of HMBA.
   
   It is important point. If the authors would not show the anaysises, I could not trast their synthesitc results.
   
   
5. The authors should explain AWS on page 7 in line 235.
   
   
6. It is hard to see the error bars in Figures 3A and 4G, H.
   
   
7. It is hard to see the gradient getting blacker toward the outside in Figure 4G, H.
8. The compound names should be listed alongside the chemical structures in Figure 1.
9. The authors should show 1H-NMR of PRE-0 to compare with PRE-10, 20, and 30 in Figure 2C.
10. The authors should show the GPC results of PRE-0. I think that Figure 2E is not necessary to show. It means that it is enough to show the results as Figure 2F.
    
    It is nessery to show the GPC results of PRE-0. If not, I can not accept the manscript.
    
    
11. The authors should explain WCA and DCA in Figure 3B, D.
12. The authors should describe which sample was used in SEM and EDS analyses in Figure 3E.
13. As I am color blind, it is difficult for me to recognize the colors of methacryloxypropyl (trimethylsiloxy) silane and triisocyanate in Figure 1. There are same problems in Figures 2C, D, E F, 3A, B, C, D, and 4H. For instance, it is difficult for me to recognize the red and green (?) vertical axes in Figure 2B. I would like to recommend changing the shape of each chemical compound in Figure 1 and changing the colors in all Figures.
    
    Pleas change color.

 

 

Author Response

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Author Response File: Author Response.pdf