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Oxide Nanostructured Coating for Power Lines with Anti-Icing Effect

Coatings 2022, 12(9), 1346; https://doi.org/10.3390/coatings12091346

by Andrey Vladimirovcih Blinov¹, Dmitry Aleksandrovich Kostyukov¹, Maria Anatolevna Yasnaya¹, Pavel Aleksandrovich Zvada¹, Lyudmila Pavlovna Arefeva², Valery Nikolaevich Varavka², Roman Aleksandrovich Zvezdilin¹, Alexander Aleksandrovich Kravtsov^1,3

, David Guramievich Maglakelidze¹

, Alexey Borisovich Golik¹

, Alexey Alekseevich Gvozdenko¹, Natalia Viatcheslavovna Lazareva⁴, Elena Nikolaevna Kushch⁴, Vadim Nikolaevich Goncharov⁵, Maxim Andreevich Kolodkin¹, Mohammad Ali Shariati⁶

and Andrey Ashotovich Nagdalian^1,7,*

Reviewer 1: Anonymous

Reviewer 2: Anonymous

Reviewer 3: Anonymous

Reviewer 4:

Xin Wu

Coatings 2022, 12(9), 1346; https://doi.org/10.3390/coatings12091346

Submission received: 26 July 2022 / Revised: 8 September 2022 / Accepted: 9 September 2022 / Published: 16 September 2022

(This article belongs to the Special Issue Protective Composite Coatings: Implementation, Structure, Properties)

Round 1

Reviewer 1 Report

I can recommend the publication of the manuscript after a minor revision.

Write in alphabetical order the keywords.

The writing can be improved, it is still poor with numerous typos or grammar mistakes.

Insert reference for the sentence, page 2: “SiO2 forms a relief structure with low surface energy, which contributes to the creation of a hydrophobic layer.”

Insert a tab at the beginning of the sentence: “2. The sequential immersion method based on alternating stages of applying tetraethoxysilane and ammonia solution....”

If possible, improve the accuracy and resolution of Fig. 1.

Insert a short discussion with explained information about Figs. 2 and 3.

Kindly insert a paragraph with Statistical analyses, and explain the method, the software used, and all the parameters related to these statistical experiments.

Insert references for all mathematical formulas.

References are not written according to the Guide of Authors (e.g., refs. [29], [37] – insert all information, and so on – minor mistake in [27]).

If possible, I recommend the following references:

[1] https://doi.org/10.1021/la301420p

[2] Țălu, Ș. (2015). Micro and nanoscale characterization of three dimensional surfaces. Basics and applications. Napoca Star Publishing House: Cluj-Napoca, Romania (pp. 21-27).

This paper presents an interesting approach and deserved to be published after the mentioned revisions.

Author Response

We are grateful to the Reviewer 1 for his/her positive evaluation and for the time devoted to review our manuscript. All comments were useful and pleased us with the high level of understanding of the topic. We have addressed all recommendations as requested. All changes in the manuscript are marked by green. Please see the point-by-point answers below

I can recommend the publication of the manuscript after a minor revision.

Write in alphabetical order the keywords.

Thank you for recommendation, we changed key words order

The writing can be improved; it is still poor with numerous typos or grammar mistakes.

Thank you for the comment. We have done our best to improve English quality.

Insert reference for the sentence, page 2: “SiO2 forms a relief structure with low surface energy, which contributes to the creation of a hydrophobic layer.”

We added: Sivolapov, P., Myronyuk, O., Baklan, D., & Berehovyj, T. Formation of effective concentration of film forming superhydrophobic coatings based on silicon dioxide. Technology Audit and Production Reserves 2021, 3(3), 59, doi:10.15587/2706-5448.2021.233535

Insert a tab at the beginning of the sentence: “2. The sequential immersion method based on alternating stages of applying tetraethoxysilane and ammonia solution....”

Corrected, thank you!

If possible, improve the accuracy and resolution of Fig. 1.

Thank you for recommendation, we improved the quality of figure 1

Insert a short discussion with explained information about Figs. 2 and 3.

Thank you for recommendation, we added short description of figures 2 and 3

Kindly insert a paragraph with Statistical analyses, and explain the method, the software used, and all the parameters related to these statistical experiments.

Corresponding information has been added, thank you!

Insert references for all mathematical formulas.

Calculations were carried out in accordance with the methodological guidelines:

Popov E.N. Mechanical part of overhead power transmission lines: Textbook. Amur State University, T. G. Blagoveshchensk, 1998, 28p (in Russian)

Handbook on the design of electrical networks. Edited by D. L. Faibisovich., 4th ed., Moscow, ENAS, 2012, 376 p. (in Russian)

Farzaneh, M., Jakl, F., Arabani, M. P., Eliasson, A. J., Fikke, S. M., Gallego, A., ... & Volat, C. (2010). Systems for prediction and monitoring of ice shedding, anti-icing and de-icing for power line conductors and ground wires.

GOST 839-2019 Non-insulated conductors for overhead power lines. Specifications. (in Russian)

The corresponding changes have been made in the main text and References section (ref. 41-44).

References are not written according to the Guide of Authors (e.g., refs. [29], [37] – insert all information, and so on – minor mistake in [27]).

Thank you for your attention. The References have been checked for mistakes. Corrections have been made to the sources 26, 27, 31, 32, 34, 35, 37 – 40.

If possible, I recommend the following references:

[1] https://doi.org/10.1021/la301420p

[2] Țălu, Ș. (2015). Micro and nanoscale characterization of three dimensional surfaces. Basics and applications. Napoca Star Publishing House: Cluj-Napoca, Romania (pp. 21-27).

Thank you for recommendation. Both sources were useful, we used them in the text.

This paper presents an interesting approach and deserved to be published after the mentioned revisions.

Thank you very much for your kind evaluation of our work!

Reviewer 2 Report

The paper on Oxide nanostructured coating for power lines with ant-icing effect, by A.V. Blinov et al., makes a complete study of a coating option for aluminium power-lines. The coating case and the study presented is of clear interest, although the novelty is not so clear.
The paper presents many test results of interest, is well presented and correctly written. It is of clear interest for publishing. However, before considering for publication, the Authors must complete the information required below. I believe that the Authors can complete these points and provide an improved version with added valuable information.

- - - - - REVIEW : general - - -

For Reviewing, the Authors should always provide a line-numbered version.

-1-
The CONCLUSIONs must clearly expose the results about the two coating options studied. Advantages and disadvantages of both options. Similarities and differences. Also insist on what is the novelty with respect to the previously reported results.
Re-make this section, including, maybe, a bulleted list.
It is also interesting to consider if the coating would be an option for other wire materials or situations.

-2-
State clearly if the coatings used in this study are a novelty or if there are some previous similar studies.

-3-
In the introduction or somewhere else, focus the study on some specific application cases. Is the analysis applicable directly to some type of Aluminium conductor steel-reinforced cable (ACSR) or ACCC (Aluminium Conductor Composite Core) or similar?
Note that the paper includes a mechanical sag analysis of a specific wire, therefore all the data should be coherent.

-4-

(on page-15)
The results mentioned and shown in Figure-16 are quite surprising. The maximum force value for the wire is about 2130 N, and 2385 N the maximum measured case. This is a change of more than 11% due to the coating. In relation of a wire of 15mm diameter, this is an equivalent extra thickness of 0.8mm (diameter): this 0.4mm for 5 layers or 80 microns per layer.
However, the rigidity modulus of the coating is probably much lower than for aluminium. Not to mention the contact effect of metal -coating. Therefore, one would expect that each layer is more than 80 microns.
Does it make any sense ?

NOTE that for the evaluation of the sagging effect, the coated-wire radius is used. How is it evaluated ? As density-diameter-weight ? Is this value compatible with the mechanical one?

If the Authors do not want to go into this discussion, at least mention the general situation and comment in your answer.

- - - - - REVIEW PAGE-by-PAGE

p2
table-1
label BRAND is useless. Remove

p3
section 2.2
The two methods 1 and 2 must be formatted properly (now -2- is mixed in the last paragraph).

p3
section 2.2
In page p5, the Authors refer to : (p5) The SiO2 nanoparticles sol obtained by the Stober method...
and in p3: Synthesis of SiO2 nanoparticles was carried out according to the following method...

If the Authors used the Stober method, it should be clearly stated in section 2.2

** note also that the sentence on p3 should start as: THE synthesis of SiO2 nanoparticles...

p3
section 2.2
It is confusing the mention:
... obtained a silicon oxide-based protective coating in two ways, depending on the application technique...
and then the methods 1. and 2.

1. making the sol and application
However the Authors mention: (THE) synthesis of SiO2 nanoparticles...
So, in point -1-: do they refer to the sol? or to the synthesis ?

2. sequential immersion
Explain clearly why applying tetraethoxysilane and ammonia solution will produce a silicon oxide-based protective coating.

p3
... the DT-1202 facility...

This model is an analyzer. Change to ...the DT-1202 analyzer...

p3
Study of structural and mechanical...

Correct to
The study of the structural and mechanical...

p3
Determination of the effectiveness of oxide coatings...

Correct to
The determination of the effectiveness of the oxide coatings...

p3
Three wire samples were placed...

It is confusing how many samples were used. Clearly, the Authors analysed coatings with 1-to-5 coating cycles, for two methods and the control sample.
But, how many samples for each (cycle) case and method ?
Maybe one sample per case and method. If so, the results are representative, but limited in the statistical value. Therefore, the Authors should state clearly this point, and consider that the results present a single measured case, and not sampling dispersion can be quoted or stated at this study stage.

If more than one sample were used, the dispersion of results should be stated.

p4 & Figures -1 -2 -3

The Authors must explain the measurement method used, no just the equipment used.
This is for the NI-BNC-2120 module and for the software used.
Present clearly 'what', and then 'how'.

p5-ff
Section-3. Results and Discussion
Consider to make a subsection for each of the studied topics for better structuring the discussion
--particles size
--mass change
--elemental composition
--morphology of the surface
--structural and mechanical characteristics
--wetting contact angle.
--icing
--signal attenuation
-- resistance
--line sagging

p5
The SiO2 nanoparticles sol obtained by the Stober method...

This comment is confusing. Check the comment above on page3 and section 2.2

p6 & Figure-4

As can be seen in Figure 4, the distribution of SiO2 nanoparticles has a unimodal character, the average size of silicon oxide particles is 90±12 nm.

Be more specific:
As can be seen in Figure 4, the distribution of SiO2 nanoparticles has a unimodal character. The average size of silicon oxide particles measured was 90 ± 12 nm (sigma?).
******Define what is the +- 12 value: sigma of whatever.

p6
... we prepared 5 batches of ABE wire samples with a different number of layers of SiO2 nanoparticles on the surface.

This is confusing: what is a sample batch ?
Complete this information according to the comment above on page-3 for samples and statistics.

It is the same in page-7:
During the experiment, 5 batches of ABE wire samples...

p8
...After the application of 5 layers of protective coating, the relative change in the weight of the ABE wire does not exceed 1%, therefore, overhead power lines will not be overloaded...

This analysis is done in detail in Section-3. It is not of interest to mention here. Otherwise, keep the attention with a different sentence:
The mechanical effect of extra weight due to the coating (always below 1%) is analysed in sub-Section-3...

p8

A comparative analysis of the change in the mass of ABE wires after the application ...
... sol changes faster after the 3rd cycle, and ... sequential immersion method changes faster after the 4th cycle.

But note that the most important change is the difference in the layer-1 and then, layer-2 -3 -4 -5.
Therefore, mention that important change after layer-2, and the rest.

p14-15 & Figure-15
...stretching diagrams were obtained for all samples.

Define briefly the test method. The elongation goes up to 6mm, however the applied force raises and decreases.
It seems that the wire is loaded till breaking ? But it seems bizarre that the shape is symmetrical. Explain clearly.

p15
...the maximum force supported by the ABE wire sample before destruction on the coating...

This is confusing. How the Authors check the destruction on the coating ?
Is the stretching test done up to the breaking of the wire ? of the coating ?
Define clearly the maximum force.

p15
...and for wire coated by immersion in SiO2 nanoparticles sol – 2190 N at 5 application cycles.

correct to:
...and for wire coated by immersion in SiO2 nanoparticles sol, the maximum sustained force was about 2190 N at 5 application cycles.

p17
... had no ice...

Specify if this was also defined after a weight measurement, as for the cases a) and b). Then, better quote a measured ice quantity value compatible with cero.

p17
The Authors refer to a new topic not mentioned before about the deterioration of the bandwidth of high-frequency communication channels. This topic should be properly introduced in the (new) sub-section, separately of all the rest.
Consider also better organizing the information on pages 17-18, since the Authors refer to priorities (page-17) which are not analysed in the paper and requirements (page 18) that neither are analysed.
Therefore, the Reviewer strongly recommends that this introduction be reduced to the minimum:
-- interest in analysing the bandwidth changes, beyond the power line use of the wires
-- what is measured (bandwidth changes), and in what range, with respect to the general requirements
Otherwise, it is confusing what the Authors try to present with the (too) general introduction and the (very) limited analysis.

p18 -19
Explain clearly the method:
-- what is measured
-- relate clearly to the section 2.2.3 about how to define the values
-- define the measurement conditions: with ice on the wires? what temperature?
-- define clearly what is and how to measure U_1, U_2, f_1, f_2 and Delta_U
-- specify also some reference value of the uncertainty of the measured values (1%, 5% ...)

p18-19
Table -5 -6 -7 & Figure -19

It seems not of interest to include all the data on the tables, since the information is in the Figure.
By removing the tables, the paper will gain by reducing this non-essential content.

p19 & Figure 20

Define R X Z for the resistance analysis.

p22
Table -10 -11
the table quotes 'MEANING'. It is maybe beter something as 'specification' or 'value'

p22 eq-3
h_w1 _w2 _w3 are not defined, and it is confusing to connect with h_w.
Since the Authors decided to explain the calculation method, it must be complete.

p22
The load of the wire's own weight,...
eq-4 : gamma_1

This parameter is a STRESS (pressure), normalized to the (wire) unit-length.
It is possible to keep 'load' but it is interesting to consider the actual magnitude for the mechanical analysis.
Check also the next comments.

p.22-23 & Table-12
The normative permissible voltage of the wire at the highest load, daN/m mm2
...at minimum temperature
...at the average annual temperature

These values seem to be the allowed wire stress values per unit-length, supposed at maximum voltage. Correct the table concept or re-define the meaning, or explain correctly.

Define what is the max-voltage considered, according to the section and wire type and specifications.
--
Check also the text on p22-23 about the same concept.

p23
eq-6
... b_cal thickness of 1 layer;

The Authors did not evaluate this thickness, probably obtained after the density, the geometry (wire diameter) and the weight.
Complete this information.

p23
From the calculations, it can be seen that 1 layer of the applied coating changes the load of 0.001 daN/m mm2...

It is much more interesting and effective to mention also the % of change in the value after adding the coating layer.

p23-24 & figure-23
The discussion about increasing the number of layers, as it is now, up to 7900 layers (!) makes no sense, and causes a bizarre effect to refer to 100's of 1000' of layers, which neither makes sense according the evaluated results for 5 layers.
The Authors explained clearly the procedure of evaluating the sag effect, and the changes due to one coating layer.
Explaining the effect of extra layers can be done in a more realistic way, and be much more effective, just reduced to the core information.
Kind of:
(calculation of 1 layer and continue and finish as)
The effect of adding coating layers results negligible. Just consider that even with 100 layers of nanostructured oxide coating on the ABE wire, the load will increase by 0.02 daN/m mm2, and the sag will only increase by 0.05 m, which will also be absolutely not critical.

No other information is needed and the discussion is sharp and clear.
(Remove also the figure 23 and refer to the % change, not only to the absolute value )

p23 Table-12
All the properties are about ABE. Therefore, change the columns labels:
Wire brand change to parameter
ABE change to value

Author Response

We are grateful to the Reviewer 2 for his/her positive evaluation and for the time devoted to review our manuscript. All comments were useful and pleased us with the high level of understanding of the topic. We have addressed all recommendations as requested. All changes in the manuscript are marked by green. Please see the point-by-point answers below

Corrected, thank you!

-1-
The CONCLUSIONs must clearly expose the results about the two coating options studied. Advantages and disadvantages of both options. Similarities and differences. Also insist on what is the novelty with respect to the previously reported results.
Re-make this section, including, maybe, a bulleted list.
It is also interesting to consider if the coating would be an option for other wire materials or situations.

Thank you for recommendations, we considered them in revision and made corresponding changes in the text

-2-
State clearly if the coatings used in this study are a novelty or if there are some previous similar studies.

Silicon oxide coatings were previously described in the world literature. However, the novelty of the work is associated with:

1) the use of nanostructured coating;

2) comparison of methods for obtaining a nanostructured coating;

3) determination of the optimal number of layers of nanostructured coating;

4) evaluation of the effect of nanostructured coating on the mechanical characteristics of power lines.

-3-
In the introduction or somewhere else, focus the study on some specific application cases. Is the analysis applicable directly to some type of Aluminium conductor steel-reinforced cable (ACSR) or ACCC (Aluminium Conductor Composite Core) or similar?
Note that the paper includes a mechanical sag analysis of a specific wire, therefore all the data should be coherent.

The calculations used are applicable for all types of cables. More details can be found in the guidelines, which we used:

Popov E.N. Mechanical part of overhead power transmission lines: Textbook. Amur State University, T. G. Blagoveshchensk, 1998, 28p (in Russian)

The sources are mentioned in Results and Discussion section.

-4-

Thank you very much for your comment! We miised this part which can be caused by the mistake in the previous experiment. To decide this issue we repeated the experiment. The tensile strength for the control wire sample was 2240 N, for samples treated with SiO2 nanoparticles sol – 2305 H, for samples treated with tetraethoxysilane and ammonia – 2385 N. The largest changes were 6.5%. It is important to note that the stiffness modulus of aluminum and silicon oxide, which is the basis of the nanostructured coating, is approximately the same (for silicon oxide from 60 to 80 GPa, aluminum from 65 to 72 GPa). Considering that the composition of the nanostructured coating includes materials with a higher modulus of stiffness of titanium oxide (more than 140 GPa) and zirconium oxide (more than 200 GPa), the modulus of stiffness of the nanostructured coating will be higher than that of aluminum. In this regard, it is quite difficult to estimate the thickness of the nanostructured coating layer. According to our experiment design in this work we used samples with the maximum number of layers = 5.

NOTE that for the evaluation of the sagging effect, the coated-wire radius is used. How is it evaluated ? As density-diameter-weight ? Is this value compatible with the mechanical one?

If the Authors do not want to go into this discussion, at least mention the general situation and comment in your answer.

Thank you for your comment. In our work, the radius of the coated wire is taken into account, the remaining parameters are determined by calculation according to:

Popov E.N. Mechanical part of overhead power transmission lines: Textbook. Amur State University, T. G. Blagoveshchensk, 1998, 28p (in Russian)

Handbook on the design of electrical networks. Edited by D. L. Faibisovich., 4th ed., Moscow, ENAS, 2012, 376 p. (in Russian)

GOST 839-2019 Non-insulated conductors for overhead power lines. Specifications. (in Russian)

- - - - - REVIEW PAGE-by-PAGE

p2
table-1
label BRAND is useless. Remove

Corrected, thank you!

p3
section 2.2
The two methods 1 and 2 must be formatted properly (now -2- is mixed in the last paragraph).

Corrected, thank you!

p3
section 2.2
In page p5, the Authors refer to : (p5) The SiO2 nanoparticles sol obtained by the Stober method...
and in p3: Synthesis of SiO2 nanoparticles was carried out according to the following method...

If the Authors used the Stober method, it should be clearly stated in section 2.2

** note also that the sentence on p3 should start as: THE synthesis of SiO2 nanoparticles...

This inaccuracy has been eliminated, thank you!

p3
section 2.2
It is confusing the mention:
... obtained a silicon oxide-based protective coating in two ways, depending on the application technique...
and then the methods 1. and 2.

1. making the sol and application
However the Authors mention: (THE) synthesis of SiO2 nanoparticles...
So, in point -1-: do they refer to the sol? or to the synthesis ?

Corrected, thank you!

sequential immersion
Explain clearly why applying tetraethoxysilane and ammonia solution will produce a silicon oxide-based protective coating.

Corrected, thank you!

p3
... the DT-1202 facility...

This model is an analyzer. Change to ...the DT-1202 analyzer...

Corrected, thank you!

p3
Study of structural and mechanical...

Correct to
The study of the structural and mechanical...

Corrected, thank you!

p3
Determination of the effectiveness of oxide coatings...

Correct to
The determination of the effectiveness of the oxide coatings...

Corrected, thank you!

p3
Three wire samples were placed...

It is confusing how many samples were used. Clearly, the Authors analysed coatings with 1-to-5 coating cycles, for two methods and the control sample.
But, how many samples for each (cycle) case and method ?
Maybe one sample per case and method. If so, the results are representative, but limited in the statistical value. Therefore, the Authors should state clearly this point, and consider that the results present a single measured case, and not sampling dispersion can be quoted or stated at this study stage.

If more than one sample were used, the dispersion of results should be stated.

All studies were carried out in a five-fold repetition (n = 5). The corresponding information has been added to the text of the article.

To determine the effectiveness of the coatings, three series of samples were used:

1 series – wires treated with a developed oxide nanostructured coating by applying alternating immersion in a solution of TEOS and ammonia,

Series 2 – wires treated with a coating applied by immersion in silicon oxide sol;

3 series – uncoated wires.

In total, 15 samples were used in this study (5 samples in a series * 3 series).

It is important to note that in this study we used samples with the maximum number of layers = 5.

p4 & Figures -1 -2 -3

The Authors must explain the measurement method used, no just the equipment used.
This is for the NI-BNC-2120 module and for the software used.
Present clearly 'what', and then 'how'.

We added description of the method, thank you for recommendation!

p5-ff
Section-3. Results and Discussion
Consider to make a subsection for each of the studied topics for better structuring the discussion
--particles size
--mass change
--elemental composition
--morphology of the surface
--structural and mechanical characteristics
--wetting contact angle.
--icing
--signal attenuation
-- resistance
--line sagging

Section 3 was divided by subsections. Thank you for recommendation!

p5
The SiO2 nanoparticles sol obtained by the Stober method...

This comment is confusing. Check the comment above on page3 and section 2.2

Corrected, thank you!

p6 & Figure-4

As can be seen in Figure 4, the distribution of SiO2 nanoparticles has a unimodal character, the average size of silicon oxide particles is 90±12 nm.

Be more specific:
As can be seen in Figure 4, the distribution of SiO2 nanoparticles has a unimodal character. The average size of silicon oxide particles measured was 90 ± 12 nm (sigma?).
******Define what is the +- 12 value: sigma of whatever.

We added clarification, thank you for recommendation!

p6
... we prepared 5 batches of ABE wire samples with a different number of layers of SiO2 nanoparticles on the surface.

This is confusing: what is a sample batch ?
Complete this information according to the comment above on page-3 for samples and statistics.

It is the same in page-7:
During the experiment, 5 batches of ABE wire samples...

We rewrote the sentences using ‘groups’ instead of ‘batches’

p8
...After the application of 5 layers of protective coating, the relative change in the weight of the ABE wire does not exceed 1%, therefore, overhead power lines will not be overloaded...

This analysis is done in detail in Section-3. It is not of interest to mention here. Otherwise, keep the attention with a different sentence:
The mechanical effect of extra weight due to the coating (always below 1%) is analysed in sub-Section-3...

Corrected, thank you!

p8

A comparative analysis of the change in the mass of ABE wires after the application ...
... sol changes faster after the 3rd cycle, and ... sequential immersion method changes faster after the 4th cycle.

But note that the most important change is the difference in the layer-1 and then, layer-2 -3 -4 -5.
Therefore, mention that important change after layer-2, and the rest.

Corrected, thank you!

p14-15 & Figure-15
...stretching diagrams were obtained for all samples.

Define briefly the test method. The elongation goes up to 6mm, however the applied force raises and decreases.

Thank you for your comment. Now a brief description of the research method is described. The increase and decrease in the load on the stretching diagram is related to the properties of the material. In this case, the material has no flow area.

It seems that the wire is loaded till breaking ? But it seems bizarre that the shape is symmetrical. Explain clearly.

During new experiment, we checked the initial experimental data. Indeed, the wire is loaded to rupture, which occurs at 1585 N for the control sample, at 1612 N for the sample treated with SiO2 sol, and at 1780 for the sample treated with TEOS and ammonia. The curve obtained in the framework of the new experiment is not symmetrical, which is clearly seen in the new graphs. Thank you for your attention, it helped us to correct mistakes in the experiment.

p15
...the maximum force supported by the ABE wire sample before destruction on the coating...

Corrected, thank you!

This is confusing. How the Authors check the destruction on the coating ?
As part of the experiment, the wire was torn, which led to the rupture of the nanostructured coating. Until the moment of rupture, the destruction of the coating was not observed.

Is the stretching test done up to the breaking of the wire ? of the coating ?

We conducted tests before the wire destruction

Define clearly the maximum force.

We rewrote it and changed to “tensile strength”.

p15
...and for wire coated by immersion in SiO2 nanoparticles sol – 2190 N at 5 application cycles.

correct to:
...and for wire coated by immersion in SiO2 nanoparticles sol, the maximum sustained force was about 2190 N at 5 application cycles.

Corrected, thank you!

p17
... had no ice...

Specify if this was also defined after a weight measurement, as for the cases a) and b). Then, better quote a measured ice quantity value compatible with cero.

Corrected, thank you!

p17
The Authors refer to a new topic not mentioned before about the deterioration of the bandwidth of high-frequency communication channels. This topic should be properly introduced in the (new) sub-section, separately of all the rest.
Consider also better organizing the information on pages 17-18, since the Authors refer to priorities (page-17) which are not analysed in the paper and requirements (page 18) that neither are analysed.
Therefore, the Reviewer strongly recommends that this introduction be reduced to the minimum:
-- interest in analysing the bandwidth changes, beyond the power line use of the wires
-- what is measured (bandwidth changes), and in what range, with respect to the general requirements
Otherwise, it is confusing what the Authors try to present with the (too) general introduction and the (very) limited analysis.

Thank you very much for recommendation, we significantly reduced this section.

p18 -19
Explain clearly the method:
-- what is measured
-- relate clearly to the section 2.2.3 about how to define the values
-- define the measurement conditions: with ice on the wires? what temperature?
-- define clearly what is and how to measure U_1, U_2, f_1, f_2 and Delta_U
-- specify also some reference value of the uncertainty of the measured values (1%, 5% ...)

Thank you for recommendation, we added corresponding information to the text

p18-19
Table -5 -6 -7 & Figure -19

It seems not of interest to include all the data on the tables, since the information is in the Figure.
By removing the tables, the paper will gain by reducing this non-essential content.

Thank you for recommendation,. We deleted these tables

p19 & Figure 20

Define R X Z for the resistance analysis.

Corrected, thank you!

p22
Table -10 -11
the table quotes 'MEANING'. It is maybe beter something as 'specification' or 'value'

Corrected, thank you!

p22 eq-3
h_w1 _w2 _w3 are not defined, and it is confusing to connect with h_w.

Thank you for comment. , , was mentioned in table 11. Determination of h_w was added to the text.

Since the Authors decided to explain the calculation method, it must be complete.

Thank you for comment. The complete calculation method will take many place in the text, that is why we used only final parts. If applicable, we added links to the references in the text, so readers will be able to refer to the methods in initial sources. Also we mentioned in the end of the article that all raw data of the experiment are available by request from corresponding author. We will be glad to share and discuss the methods and data with readers

p22
The load of the wire's own weight,...
eq-4 : gamma_1

This parameter is a STRESS (pressure), normalized to the (wire) unit-length.
It is possible to keep 'load' but it is interesting to consider the actual magnitude for the mechanical analysis.

Corrected, thank you!

Check also the next comments.

Thank you for your comment, We changed the conceptualization of the table 12.

p.22-23 & Table-12
The normative permissible voltage of the wire at the highest load, daN/m mm2
...at minimum temperature
...at the average annual temperature

These values seem to be the allowed wire stress values per unit-length, supposed at maximum voltage. Correct the table concept or re-define the meaning, or explain correctly.

Thank you for your comment, We changed the conceptualization of the table 12

Define what is the max-voltage considered, according to the section and wire type and specifications.
--
Check also the text on p22-23 about the same concept.

Max-voltage is shown in Table 12. According to GOST 839-2019 Non-insulated conductors for overhead power lines. Specifications max-voltage should be determined and declare by the wire manufacturer. The stress of the wire's own weight was determined using formula (4).

p23
eq-6
... b_cal thickness of 1 layer;

The Authors did not evaluate this thickness, probably obtained after the density, the geometry (wire diameter) and the weight.
Complete this information.

Thank you for your comment. The F_calvalue is a reference obtained from [44]. We added corresponding information.

p23
From the calculations, it can be seen that 1 layer of the applied coating changes the load of 0.001 daN/m mm2...

It is much more interesting and effective to mention also the % of change in the value after adding the coating layer.

Corrected, thank you!

p23-24 & figure-23
The discussion about increasing the number of layers, as it is now, up to 7900 layers (!) makes no sense, and causes a bizarre effect to refer to 100's of 1000' of layers, which neither makes sense according the evaluated results for 5 layers.
The Authors explained clearly the procedure of evaluating the sag effect, and the changes due to one coating layer.
Explaining the effect of extra layers can be done in a more realistic way, and be much more effective, just reduced to the core information.
Kind of:
(calculation of 1 layer and continue and finish as)
The effect of adding coating layers results negligible. Just consider that even with 100 layers of nanostructured oxide coating on the ABE wire, the load will increase by 0.02 daN/m mm2, and the sag will only increase by 0.05 m, which will also be absolutely not critical.
No other information is needed and the discussion is sharp and clear.
(Remove also the figure 23 and refer to the % change, not only to the absolute value )

Thank you for your comment, we agree with all point and decided to delete figure 23 and all information associated with it.

p23 Table-12
All the properties are about ABE. Therefore, change the columns labels:
Wire brand change to parameter
ABE change to value

Corrected, thank you very much!

Reviewer 3 Report

Comments of coatings-1860301

The main weaknesses of the manuscript:

1. Introduction part: “Therefore, the purpose of this work was to develop a technique to obtain a nanostructured oxide coating to protect power lines from icing”. Only one sentence describes the purpose, and it is recommended to elaborate more details and planning.

2. Figure 13. SEM micrographs of the surface of a sample containing 5 layers of protective coating applied by immersion in SiO₂ nanoparticles sol. Need to revised Figure “14”.

3. Figures 9 to 11 are suggested to be combined into 1 figure; Figures 12 to 14 are suggested to be combined into 1 figure. For the results of SEM surface topography, the differences should be discussed and compared.

Comments for author File: Comments.pdf

Author Response

We are grateful to the Reviewer 3 for his/her positive evaluation and for the time devoted to review our manuscript. All comments were logical and relevant. We have considered all recommendations. All changes in the manuscript are marked by green. Please see the point-by-point answers below

The main weaknesses of the manuscript:

Introduction part: “Therefore, the purpose of this work was to develop a technique to obtain a nanostructured oxide coating to protect power lines from icing”. Only one sentence describes the purpose, and it is recommended to elaborate more details and planning.

Thank you for recommendation! We added information to the sentence

Figure 13. SEM micrographs of the surface of a sample containing 5 layers of protective coating applied by immersion in SiO2 nanoparticles sol. Need to revised Figure “14”.

Thank you, corrected!

Figures 9 to 11 are suggested to be combined into 1 figure; Figures 12 to 14 are suggested to be combined into 1 figure. For the results of SEM surface topography, the differences should be discussed and compared.

Thank you for recommendation!

Figures 9-11 and 12-14 in this manuscript are necessary in order to show the differences in the structure and topology of the samples with a different number of layers of nanostructured coating applied and with a different coating method. Different magnifications are used, which make it possible to observe differences both in the microstructure of the samples and in the microstructure. In our opinion, combining the figures into one will cause confusion and make it difficult for the readers. When removing a part of microphotographs with different approximations, part of the information about either the macrostructure or the microstructure of the samples will be lost. Therefore, dear Reviewer, we thank you for your recommendation, but with your consent, we would like to leave the figures in their current position.

Reviewer 4 Report

In the paper "Oxide nanostructured coating for power lines with ant-icing effect", the authors developed an anti-icing coating for use in the electric power industry. The work is somehow comprehensive and interesting, while some improvement needed to be conducted to further enhance the conclusions.

1) Some useless information should be deleted, such as Figures 1,2,3, which should not be the focus of the conducted study, and the description like the first paragraph should be condensed.

2) In Section 2, besides deleting Figures 1-3, there should be a diagram describing the preparing procedure of the coatings, and there should better be a figure describing the overall morphology of the overhead wires with coatings. Those should be the focus of your study.

3) As for the studies related to coatings, it is usually needed to provide some cross-section morphologyies to describe the thickness and uniformness of the coating.

4) Sentence such as "Based on the analysis of SEM micrographs of samples with the different number of layers ..." is too rude because it is hard to obtain some determined conclusions from only the surface morphology.

5) How many tested pieces are used for averaging to get the error bar information?

6) For the results such as in Figure 16, error bar information should be provided.

Author Response

We are grateful to the Reviewer 4 for his/her positive evaluation and for the time devoted to review our manuscript. All comments were logical and relevant. We have considered all recommendations. All changes in the manuscript are marked by green. Please see the point-by-point answers below

1) Some useless information should be deleted, such as Figures 1,2,3, which should not be the focus of the conducted study, and the description like the first paragraph should be condensed.

Thank you very much for the comment! In our opinion Figures 1-3 are necessary to describe the methodology of conducting an experiment to study the effect of a nanostructured coating on the resistance of an ABE wire. However, we agree that origin manuscript should be revised by reduction of not relevant information. Revised version of the manuscript is shorter and more concrete.

Thank you for recommendation. We created figures describing the preparing procedure of the coatings (Figure 1 and Figure 2).

3) As for the studies related to coatings, it is usually needed to provide some cross-section morphologyies to describe the thickness and uniformness of the coating.

Thank you very much for the comment! As part of the research, we tried to conduct a study of the morphology of the cross-section, but when cutting the wire, the destruction of the nanostructured coating layer occurred. We consider your recommendation logical and relevant, but unfortunately, not suitable for our experiment.

Thank you for the comment. We agree and deleted the sentence

5) How many tested pieces are used for averaging to get the error bar information?

In the study, all experiments were carried out in a five-fold repetition. The corresponding information was added to the text.

6) For the results such as in Figure 16, error bar information should be provided.

Corrected, thank you very much!

Round 2

Reviewer 2 Report

The Authors have made an important effort to improve the draft following the recommendations of the different Reviewers.

The Reviewer still insists on the points below. Please, consider the next points to add information to the draft.

-1-

About the novelty of the paper, the Authors answered to the Reviewer:

...However, the novelty of the work is associated with:

1) the use of nanostructured coating;

2) comparison of methods for obtaining a nanostructured coating;

3) determination of the optimal number of layers of nanostructured coating;

4) evaluation of the effect of nanostructured coating on the mechanical characteristics of power lines.

These comments are very interesting to be included in the text (introduction) to highlight the novelty in a straight way for all the Readers.

-2-

About the sampling number of specimens:

L237 or L251

...During the experiment, we prepared 5 groups of ABE wire samples with a different number of layers.

How many specimens of each type ? That will define the statistical spread of the data (if more than one specimen per type). If only one specimen is tested for each case, it should be also stated clearly in the text to avoid any misunderstanding.

Author Response

Dear Reviewer,

thank you very much for kind evaluation of our work.

We added information about novelty of the work in the end of Introduction section, as a consequence of the purpose of the work.

Also we added information about number of samples in aech group as was kindly recommended.

Thank you one more time for your valuable comments and recommendation which helped us to improve the quality of our work.

Reviewer 4 Report

I am satisfied with the response.

Author Response

Dear Reviewer,

Thank you very much for kind evaluation of our work!

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Oxide Nanostructured Coating for Power Lines with Anti-Icing Effect

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