Experimental Investigation on the Wear Performance of Nano-Additives on Degraded Gear Lubricant

Round 1

Reviewer 1 Report

1. The oxidation stability of lubricants with nano-additives should be studied.

2. In a large number of published references, graphene has been shown to exhibit superior friction reduction and wear resistance compared to graphite when introduced into lubricating oil. Why do the opposite results appear in Table 4?

3. As shown in Table 6, the wear mass decreases with the increase of GO@SiO₂ addition. Therefore, higher filler additions should be investigated.

4. The authors should give scientific and reasonable explanations for all experimental results and phenomena, rather than just listing experimental results.

5. More characterization methods (such as XRD, TEM and Ranman, etc.) should be used to further analyze the structure and morphology of the nano-additives to support the subsequent research and analysis.

6. The size and layout of the pictures should be more uniform and reasonable.

7. The influence of friction environment (temperature, friction rate, load and friction material, etc.) on the service life and stability of lubricating oil should be mainly discussed.

8. More relevant references published in the journal of lubricants should be cited.

9. The quality of English needs major revisions both in the grammar and typo.

10. The references format should be unified.

Author Response

Dear Reviewer,

Thank you for taking the time to review our manuscript. We appreciate your feedback. we have taken it into consideration as we revised our work. We hope that our revisions address any concerns you had with the paper. Please let us know if there is any additional information or clarification we can provide to assist you in your review. We look forward to the opportunity to resubmit our manuscript for your further consideration.

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Title: 

-       The title should be revised regarding the language used. 

 

Abstract: 

-       The following information is very specific and detailed for an abstract “(Packet 1:: March 2022:pH 5.742, TAN 0.0595 mg KOH/g ; Packet 2:: June 2021:pH 4.786, TAN 8 0.069 mg KOH/g))”

-       How valid and how close to reality is the following approach “An artificial lubricant aging chemical process (mixing the 0.0025%v/v HCl)”

-       The abstract contains a lot of information about the conducted research, but less information related to the take home message is available. Please revise. 

 

Keywords: 

-       The selected keywords are fine. 

 

Introduction:

-       Please introduce all abbreviations when used for the first time. 

-       The introduction and the entire manuscript needs a very careful language revision. 

-       The state of the art regarding the use of nano-additives (2d materials) as lubricant additives is poorly described and underpresented. In this regard, authors are advised to refer to the following state of the art publications:

-       -- Layered 2D Nanomaterials to Tailor Friction and Wear in Machine Elements—A Review

-       -- Roadmap for 2D materials in biotribological/biomedical applications–A review

-       -- 2D nano-materials beyond graphene: from synthesis to tribological studies

-       The novelty of the article must be better worked out. 

-       Authors need to provide a good justification why the mentioned HCl treatment is representative for the respective purpose of ageing. 

 

Section 2: 

-       Related to Figure 1, is there really a mathematical connection between ph and time or is it just fitting purpose without any physical meaning? The same holds true for equation 2 presented. 

-       The correct abbreviation for arbitrary units is arb. u. and not a. u. 

-       The layout and design of Figure 2 is impossible. Most of the details are not readable.

-       The justification given in “Selection of nano-lubricant:” read rather questionable. Given argumentation should be rethought and rewritten. 

-       All SEM micrographs should be presented with scale bars only. 

-       Almost no information about the used nanomaterials is presented. The used additives must be holistically characterized to fully understand their effect on the resulting friction performance. The provided information is highly insufficient. The nanoadditives must the chemically, morphologically, and structurally fully characterized. 

-       Figure 6 cannot be presented in a scientific article. The quality of the images taken is insufficient. 

-       The manuscript structure is somehow questionable and it reads intermixed. Please try to work on a better structure. 

-       What was the purpose of using “graphene oxide functionalised with silicon oxide”

-       No information about the functionalization process has been provided. 

-       No information about the used silicon oxide has been provided. 

-       Why have you used 0.5 wt-%?

-       All experimental data must be provided with mean values and error bars. 

-       Please provide the wear volume instead of the lost weight. 

-       The layout of Figure 10 must be improved. 

-       Conclusions are very extensive and should be shortened. 

-       The manuscript is purely descriptive and does not present a profound interpretation neither a discussion of the results obtained. 

Author Response

Dear Reviewer,

Thank you for taking the time to review our manuscript. We appreciate your feedback and have taken it into consideration as we revised our work. We hope that our revisions address any concerns you had with the paper.

Please let us know if there is any additional information or clarification we can provide to assist you in your review. We look forward to the opportunity to resubmit our manuscript for your further consideration.

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The author has made a comprehensive revision to the question we raised, which is recommended to be accepted.

Author Response

Thank you for taking the time to review the manuscript. We appreciate your valuable feedback and suggestions, which helped to improve the quality of the manuscript.

Thank you again for your time and consideration.

 

"Please see the attachment."

Author Response File: Author Response.docx

Reviewer 2 Report

Thanks you very much for revising the manuscript. The quality of the submission has certainly improved. 

 

The Raman analysis should be extended. 

More information about the x, y and z dimensions of the used nanomaterials should be included. 

The scientific discussion of the obtained results should be extended. 

 

Author Response

Thank you for taking the time to review the manuscript. We appreciate your valuable feedback and suggestions, which helped to improve the quality of the manuscript.

Thank you.

 

"Please see the attachment."

Author Response File: Author Response.docx