Enhancing Coating Adhesion on Fibre-Reinforced Composite by Femtosecond Laser Texturing

Round 1

Reviewer 1 Report

Title: 

-       The title reads rather bulky and needs a proper language revision. Please revise and streamline. 

 

Abstract:

-       The abstract should start with a brief motivation and introduction into the entire research topic. 

-       Please avoid the usage of abbreviations in the abstract since it is a stand alone part of each scientific article. 

-       The abstract reads confusing and needs revision from the language and logic. 

 

Keywords: 

-       The selected keywords are fine. 

 

Introduction: 

-       The second paragraph of the introduction would require some better referencing.

-       Related to fs-texturing and adhesion, a recent review paper by Costa et al. is missing in the state of the art. In this regard, you may refer to: Tailored surface textures to increase friction—A review

-       Authors are advised to better work out the novelty of the presented study. 

 

Experimental and results:

-       Please provide the full experimental details related to “was applied with an aerograph”

-       Please check the following reference “The contact angle (CA) measurements were performed at 23°C in compliance with the ASTM D7490–13 [Error! Reference source not found.]”

-       Please check the following “(Figure 2Error! Reference source not 145 found. (b) and (d)). “

-       Is the following sentence correct? “This can be ascribed to the abrasion” Authors may wish to refer to ablation, right?

-       Authors should properly explain how you obtain the values for SFE?

-       How does the roughness affect these measurements (contact angle and SFE)?

-       What is the explanation for the following observation “However, these values are slightly lower than that measured for the untreated coated surface C, in spite of the uniformity of the applied coating.”?

-       Please provide mean values and error bars in Table 5?

-       There is no chemical analysis of the treated surfaces. How does fs-texturing affect the surface chemistry? This question must be answered since surface chemistry is decisive for contact angle and surface free energy measurements. 

-       Conclusions are very long and should be shortened as well as streamlined. 

-       There is no real discussion and deeper interpretation in the entire manuscript. This must be improved to make the paper publishable. 

English requires moderate polishing. 

Author Response

Please see the attachment

Author Response File: Author Response.docx

Reviewer 2 Report

The paper deals with the adhesion enhancement of a superhydrophobic coating (SHC) on CFRP through fs laser micromachining. The paper is not well prepared and should be carefully checked for typographical and editorial errors. The main problem with the paper is that nothing is mentioned about the superhydrophobic coating. The authors claim that the data are protected by a patent, but this also makes the manuscript unfit for publication. The authors focus on laser treatment, however it appears that superhydrophobic coating (SHC) plays an important role in targeted application as passive ice protection. The difference in the measured contact angles after cleaning and in the dynamic rolling test was attributed to the better adhesion of the superhydrophobic coating to the substrate. However, it could be attributed to a possible difference in morphology of the applied superhydrophobic coating due to the difference in substrate roughness (changed through laser treatment!). Since the authors only show low-magnification images of the SHC, no definite explanation can be inferred. The adhesion of SHC was also not verified by SEM or other experimental technique (for example a mechanical test such as impact test). Dynamic wettability and static wettability are not considered suitable for evaluating the adhesion of a coating. Furthermore, it appears that the author is referring to the delamination or detachment of the SHC coating rather than the adhesion of the SHC coating which is a different property. The authors should provide more information (especially SEM images) about the SHC coating and how the laser treatment affects its morphology, as it appears that the laser treatment reduced the water contact angle.

There are other issues also in the manuscript such as

-Lines 131-132: Therefore, the Surface Free Energy (SFE) has been calculated as sum of the polar and 131 dispersive components [30]. Please explain in detail how the SFE was calculated in table 3.

C/O content in table 2. EDX is not a suitable technique to measure such light elements as C and O. Therefore, these values cannot be considered as reliable ones.

Conclusion must be re-written to contain only the most important results and conclusion.

“Error! Reference  source not found, Error! Reference source not found” can be seen in several lines in the manuscript!

Repeated information is displayed in both figures and tables. Only one (either the table or the image) should be kept.

Author Response

Please see the attachment

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Authors have satisfactorily addressed all my comments and concerns. 

 

 

Language quality is ok. 

Reviewer 2 Report

The submitted paper can be published in the current form, since the authors made all the appropriate changes to their manuscript according to reviewer's recommendations and they replied satisfactorily to all questions.