Study on the Growth and Properties of Electrolessly Deposited Thin Copper Coatings on Epoxy-Based CFRP

Round 1

Reviewer 1 Report

All my remarks refer to the references cited.

1.
Is it really necessary to use websites as a reference?
If so, the authors should create an archive of the cited website.

2.
Article titles should be written in the same way.
Compare reference [1] >>The combination of carbon nanotube buckypaper and insulating adhesive for lightning strike protection<<
with the following references:
[2] (line 539) >>Common Type of Damages in Composites and Their Inspections<<;
[8] (line 554) >>Preparation of Metal-Coated Carbon Fiber Reinforced Composites and Their Electromagnetic Properties<<;
[15] (line 572) >>Electroless Deposition of Copper<<;
[17] (line 576) >>Sheet Resistance: A Guide to Theory<< and not: >>Sheet Resistance Equations and Theory: Complete Guide<<
(the last case shows how website resources can change)

3.
Line 551: after the word: >>Carbon<< needless characters: >>N.Y.<<

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript ‚Study on the growth and properties of electrolessly deposited thin copper coatings on epoxy-based CFRP‘ deals with the investigation of such copper films focussing on film morphology, conductivity, adhesion and chemical stability.

The work is thoroughly pursued and described in detail and I recommend this article for publication in coatings after minor amendments:

1. One major drawback of the created copper films seems to be the inhomogeneity, in particular the huge film roughness. Already after sensitisation, the surface roughness is largely increased compared to the untreated CFRP, as shown in Figure 3. What are the options to improve Sn-deposition in this early stage? Is there a way to just remove the largest grains, if formation cannot be avoided? This should be discussed in the manuscript!

2. In correlation with these possible improvements (Point 1): Chapter 3.1 states that surface wettability changes and surfaces become more hydrophilic during the process. Contact angle measurements with water should be added here! Maybe they already reveal surface inhomogeneities.

3. Figure 5 + its description: Deposition times are not clear from the Figure caption nor the text. Also the reference S3 should be explained again at this point. Are Figure 5 c and d the same sample?

4. Figure 6: Scales in c-e are not visible, especially the scale perpendicular to the sample surface would be interesting to see.

5. Figure 7: This means that surface roughness and film thickness are basically the same! Are films really fully surface-covering? see point 1: this needs to be improved and might also improve chemical resistivity!

6. The whole manuscript is well written, however not very much on point. E.g. explanation of sheet resistance measurements in such detail are not adequate (page 10, line 334-348), experimental details of the same (page 10, lines 349-357) should be part of the experimentals section. The same holds for the separation resistance: page 12 line 425-440 should be shortened and part of experimentals.

Also there are many repetitions, e.g. on Cu nuclei formation and coalescence, or procedures (page 9, line 321-328), or page 11, lines 382-388, or page 12, lines 451-455.

Significant shortening would make the manuscript much better readable and eliminates this text-book character.

7. There is a problem with symbols in resistance (page 9, bottom and following).

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

All former concerns were adequately answered and, in my opinion, the manuscript can now be published.