Droplet Dynamics and Freezing Delay on Nanoporous Microstructured Surfaces at Condensing Environment
Round 1
Reviewer 1 Report
This manuscript deals with superhydrophobic surfaces consisting of nanoporous microstructured CNT pillars. The research concept and design are outstanding, and the results are very interesting. This manuscript is therefore acceptable for publication in the present form.
The following points should preferably be reconsidered prior to publication.
1) P. 7, line 1: Fig 2a → Figure 2a
2) The caption of Fig. 4: b) on various (samples)
3) Fi. 5a): Many small spots can be seen in the air pockets (bottom area). Explain what are these.
4) The effect of the column height is interesting. Is there any threshold height for allowing for the easy coalescence of the droplets?
Author Response
The authors would like to thank all the reviewers for their valuable and constructive comments on the manuscript. In our attempt to address each comment, we feel that it has resulted in an improvement in the quality of the manuscript. The following lists the details of the changes made to the manuscript and an address to each comment. All changes are marked up using the “Track Changes” in the revised manuscript.
REVIEWER 1
This manuscript deals with superhydrophobic surfaces consisting of nanoporous microstructured CNT pillars. The research concept and design are outstanding, and the results are very interesting. This manuscript is therefore acceptable for publication in the present form.
The following points should preferably be reconsidered prior to publication.
1) P. 7, line 1: Fig 2a → Figure 2a
Response 1: Changed "Fig 2a" to "Figure 2a" in line 272.
2) The caption of Fig. 4: b) on various (samples)
Response 2: Added "samples" in the caption of Figure 4 b.
3) Fi. 5a): Many small spots can be seen in the air pockets (bottom area). Explain what are these.
Response 3: As suggested by the reviewer, an explanation is added in line 458-460 in the revised manuscript.
4) The effect of the column height is interesting. Is there any threshold height for allowing for the easy coalescence of the droplets?
Response 4: We show that, when the sizes of the micropillars are in the scale of the droplet sizes in the cavities, the droplets in the cavities overgrow and form Cassie state after coalescing with the condensate droplets on top of the micropillars. These larger size droplets can be easily moved due to external natural forces or a gentle blow. A numerical and/or calculative analysis for theorizing a threshold height for allowing easy coalescence of the droplets is out of scope of our study. However, we added new statements at the revised manuscript in line 375 suggesting this as a future study.
Reviewer 2 Report
This is very interesting research on the behavior of droplets on the microstructured surfaces at condensing environment. The manuscript fits the profile of the journal. The research can be recommended for the publication in Coatings after taking into account the following comments/suggestions:
1. Introduction - there is also a number of papers dealing with the hydrophobization of ceramic membranes by perfluorosilanes, with the interesting discussion about the behavior of surfaces using the Cao diagram. This should be also added to the introduction part.
2. The goal of the research should be improved (lines 92-109) because it is mixed to some extent with results and conclusions.
3. Figure captions must be kept short and informative. In fact Authors added also the additional comments/explanations which can be a part of the text not figure caption (e.g. Fig. 1, 2, 3, 4...)
Recommendation: minor revision
Author Response
The authors would like to thank all the reviewers for their valuable and constructive comments on the manuscript. In our attempt to address each comment, we feel that it has resulted in an improvement in the quality of the manuscript. The following lists the details of the changes made to the manuscript and an address to each comment. All changes are marked up using the “Track Changes” in the revised manuscript.
REVIEWER 2
This is very interesting research on the behavior of droplets on the microstructured surfaces at condensing environment. The manuscript fits the profile of the journal. The research can be recommended for the publication in Coatings after taking into account the following comments/suggestions:
Point 1: Introduction - there is also a number of papers dealing with the hydrophobization of ceramic membranes by perfluorosilanes, with the interesting discussion about the behavior of surfaces using the Cao diagram. This should be also added to the introduction part.
Response 1: As suggested by the reviewer, we added new statements in the introduction (lines 70-73) and new references on ceramic based hydrophobic surfaces. Ceramic membranes coated and grafted by perfluorosilane, which showed durable and scalable hydrophobic surfaces, are potential candidates in condensation conditions. The authors thank the reviewer for the suggestion to include them in the article.
Point 2: The goal of the research should be improved (lines 92-109) because it is mixed to some extent with results and conclusions.
Response 2: The goal of the research is modified in line 105-117 in the revised manuscript. Thanks for the suggestion.
Point 3: Figure captions must be kept short and informative. In fact Authors added also the additional comments/explanations which can be a part of the text not figure caption (e.g. Fig. 1, 2, 3, 4...)
Response 3: As suggested by the reviewer, figure captions for the Fig. 1, 2, 3, 4, 5, and 6 are shortened by removing lines. We ensured that these statements are added to the text of the manuscript as suggested by the reviewer.
Reviewer 3 Report
1. English is fine
2. Pictures are fine
3. Content is interesting
4. Many papers about SLIPS and hydrophobicity and ice-phobicity and this one will be well cited in coming years
5. Only point is that its hard to find the number of trials and that the lag time for a given supercooling is very varied and readers will want to know n and sigma
Author Response
The authors would like to thank all the reviewers for their valuable and constructive comments on the manuscript. In our attempt to address each comment, we feel that it has resulted in an improvement in the quality of the manuscript. The following lists the details of the changes made to the manuscript and an address to each comment. All changes are marked up using the “Track Changes” in the revised manuscript.
REVIEWER 3
1. English is fine
2. Pictures are fine
3. Content is interesting
4. Many papers about SLIPS and hydrophobicity and ice-phobicity and this one will be well cited in coming years
5. Only point is that its hard to find the number of trials and that the lag time for a given supercooling is very varied and readers will want to know n and sigma
Response: We added the number of trials in Line 386 in the revised manuscript. The “n” and “sigma” values of direct freezing delays and condensation followed by freezing delays are provided in Supplementary Material (Table S2).
