Stability and Tribological Performance of Nanostructured 2D Turbostratic Graphite and Functionalised Graphene as Low-Viscosity Oil Additives
, Diego Berti Salvaro 1, Cristiano Binder 1, Aloisio Nelmo Klein 1 and José Daniel Biasoli de Mello 1,3,*
Round 1
Reviewer 1 Report
The paper presents a study on the stability and tribological performance of nanostructured 2D turbostratic graphite and functionalized graphene as
low-viscosity oil additives. The paper is well written. I recommend acceptance after minor revisions.
1. Please give the detailed information of tribological tests, including test conditions (speed and load, etc), temperature.
2. Does the load or speed condition influence the test results?
3. What suspensions are used? just after dispersion, or later?
Author Response
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Reviewer 2 Report
This paper developed a processing route to obtain 2D turbostratic graphite particles via solid-state reactions between B4C and Cr3C2 (GBC) and between SiC and Fe (GSF) that presented nice tribological properties at a dry scenario.The lubrication performance of GBC, GSF and functionalized graphene (GNH) as lubricants were investigated. Authors demonstrated that the GBC particles remained remarkably stable and reduced 61.8 % of the sphere wear rate. From the tribosystem point of view, the presence of GBC and GSF reduced the wear rate by 18.4 % and 2.2 %, respectively, while the GNH particles increased the wear rate by 4.2 %. Furthermore, the wear rate was improved due to the highly disordered carbon tribolayer formation identified on both surfaces. Comments should be addressed.
1. In Fig.4. why GBC has significant light transmission on the first and second days, but not after 30 days? Repeating experiment is required.
2. The coefficient of friction of GBC in POE is even slightly higher than that of pure POE, so why not choose other base oils?
3. What is the meaning of friction reduction by using GBC as additives?
4. Both GSF and GNH counter-body wear rates were reduced relative to pure POE, why their wear volume on specimens was higher relative to pure POE? Additional experiments are required to repeat the results.
5. Language needs to be polished, for example “Recently, novel processing routes were developed to obtain 2D turbostratic graphite particles via solid-state reactions between B4C and Cr3C2 (GBC) and between SiC and Fe (GSF) that present outstanding tribological properties at a dry scenario. as well as functionalized graphene (GNH)”.
6. Comprehensive discussion is required for the mechanism of friction and wear reduction of the GBC, GSF and GNH lubricant additives. Relative references about antifriction and antiwear lubricant additives demonstrated detailed mechanism, which need to be cited [Spear et al, Nano Today 10 (2015) 301–314], [Wu et al, Chemical Engineering Journal 410 (2021) 128306] and [Dai et al, Tribol. Int. 102 (2016) 88–98]
Based on above comments, I suggest a major revision of the paper before publication.
Author Response
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Reviewer 3 Report
In the manuscript titled "Stability and Tribological Performance of Nanostructured 2D Turbostratic Graphite and Functionalized Graphene as Low-Viscosity Oil Additives " authors describe that from the tribosystem point of view, the presence of GBC and GSF reduced the wear rate by 18.4 % and 2.2 %, respectively, concerning pure oil, while the GNH particles increased the wear rate by 4.2 %. urthermore, the wear rate was improved due to the highly disordered carbon tribolayer formation identified on both surfaces.
However, the manuscript appear poor in the introduction and in the conclusion. The authors must compare your results with many results present in the literature and must improve the description of novelty of work. The work is appear as simple description of results, without discussion and interpretation.
Line 97) The author should more clearly discuss the main objective of the present study and sugesst potential applications and merits of carbon nanomaterials.
Line 107) The main compositions of by carbon nanomaterials must be discussed. It is better to add EDX analysys of materials.
Line 103) The procedure for the synthesis of carbon materials should be briefly discussed.
Line 101) The full names of SEM should be clarified. In addition, procedures for SEM observations should be discussed, including the preparation of specimens and operation conditions.
Line 143) More information on “LUMiSizer” should be included.
Line 173) More information on “NewView 7300” and "DM4000, Leica Microsystem" should be included and procedures for test should be discussed.
Line 234) The procedures for measurement of evolution of light transmission profiles should be discussed.
Questions:
1. Did the authors tried other concentrations above 0.05%?
2. The measurement error bar is obtained using the same specimen or different specimens? Clarify.
For this, the manuscript can be published after major revision, and an important improving of text.
Author Response
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Round 2
Reviewer 2 Report
no
Reviewer 3 Report
In this form paper may be published.
