A Review of Geometry, Construction and Modelling for Carbon Nanotori
Round 1
Reviewer 1 Report
First of all, I would like to thank Editor and authors for invitation of reviewing this Review paper. I believe I and other potential readers, we all hope to learn a lot more from a review paper than any other invidual research articles.
As carbon-based nanomaterials are becoming more and more important, a review on one of the most interesting carbon nanostructures, carbon Nanotori, is indeed needed. The article is therefore publishable after minor revision as commented below:
1. The first point is title “gfonteometry, construction and modelling” and the definition of “carbon nanotori”. If we google “carbon nanotori” -> about 5000 results appear; “carbon nanotorus” gives about 2000 results and “toroidal carbon nanotubes” give 3000 results. This is quite little compared to that of carbon nanotubes (8.000.000 results). Thus, it will be much more helpful for readers if the authors can give clear definition of “nanotori” in the Introduction part. History of carbon nanotori with typical diameters between 300 and 500 nm grown by using the laser growth method, reported by Nature article of Liu in 1997, should also be mentioned.
2. About the preparation/fabrication methods, the authors did mention in the abstract and Introduction that “It is scientifically conceivable that these crop circles, nowadays referred to as carbon nanotori, can be formed by bending carbon nanotubes into ring shaped structures or by connecting several sections of carbon nanotubes.” This sounds to me like someone can use their hands to bend the carbon nanotubes and shape a ring. It is however not the case. Pretending that the readers are not experts in the field, this may lead to confusion. I suggest that the authors make clear between experimental methods and modelling methods to “produce” carbon nanotori. They should briefly introduce experimental methods, such as organic reactions, chemical vapor deposition, laser growth, depositing hydrocarbon films in Tokamak T-10, etc…and then Structural models, in which, for example, Dunlap (1992) proposed to construct the structural model of a carbon nanotorus by connecting two CNTs with different diameters. Line 26: ref. 7 “A molecular mechanics analysis of the buckling behavior of carbon nanorings under tension” did not cover the discussion points about “many novel properties, particularly in electronic and magnetic applications”. Please revise.
3. Part 2. Physical roles, properties and applications: generally, need more exact information.
Please do use the experimental references as well since they are quite different. For example: Science, 277 (1997), p. 1971; Science, 287 (2000), p. 637…. For example: Page 2, line 50: The authors wrote: “Carbon nanotori possess the same physical properties which are common to those of carbon nanotubes and other carbon nanoparticles, such as high thermal conductivity [10] and high tensile strength [11].” -> I have checked the ref. 10: “Stability of carbon nanotori under heat treatment: Molecular-dynamics simulations.” and ref. 11: “Mechanical properties of connected carbon nanorings via molecular dynamics simulation”. These are all modelling based informationen.
- Please also add a table with numbers for each physical property with the comparision with carbon nanotubes in corresponding sizes/geometry, so that readers know how much are “high” thermal conductivity and tensile strength... Moreover, due to variable geometry of carbon nanotubes as well as carbon nanotori, we have more than just 1 value for each type.
- Figure 1 and 2 in the same page please, they are all about the electronic properties. If possible, please find a better, higher resolution picture for Fig.2.
- Line 60-65: The authors wrote “the carbon nanotori are metals if…” -> What do they mean? Carbon natori is not metal. I would say it has metallic characteristics. As exactly as ref. 14 wrote “In the case without deformations and magnetic field, using equation (9) we deduce a simple rule, i.e., the geometric parameters of the chiral metallic carbon nanotori satisfy m−n = 3i and p−q = 3i (i is an integral), the chiral semiconductor tori satisfy m−n = 3i and and the chiral insulator tori satisfy and p−q = 3i. We may also verify that the tori with and do not exist.”
- From Line 82-100, magnetic properties: Again, the discussion is quite general saying: “strongly dependent upon their size, curvature….”; “small magnetic flux”; “the magnitude of the moments decreases dramatically with increasing temperature” -> How small, strong, and dramatically are they?. The authors did cite good references, however, please extract much more crucial information/figures/numbers that relevant to discussion to better illustrate their text. For example: Figure of Induced magnetic moment as a function of temperature for various toroidal CNTs in a perpendicular magnetic
- field of 0.1 T and 0.2 T (Liu L, Guo GY, Jayanthi CS, Wu SY. Colossal Paramagnetic Moments in Metallic Carbon Nanotori. 88, 217206 (2002).
- Line 104: “The results show that” ? Please clearly mention which kind of date/result
4. Page 5, part 3. Geometry and construction of carbon nanotori: Please illustrate “small” vs. “large” carbon nanotori with picture/drawing/figures in which the information about radius and angles are included.
- Line 161-164: Please do mention that those “techniques” are modelling techniques to construct the nanotori, not experimental methods or techniques.
5. Part 4. Lennard-Johnes potential and Continuum approximation
- Line 105: I could not find the same equation or similar in the ref.9. Please cite the article from which the authors took this equation.
- Please move Fig. 5 to page 6, together with Fig.4 and correct the Figure caption: “Expertimentally determined carbon nanotorus constructed from bending a nanotube” -> again as discussed above, please delete “constructed from bending a nanotube”. As wrote in Ref 38: the figure is simply a “Scanning force micrograph of a 'crop circle', imaged with a pyramidal SFM tip (the effect of a double tip can be seen at the top and bottom). The circle has an apparent height of 1.0-1.2 nm and width of 4-8 nm.” The authors in this paper said “While examining laser-grown single-wall carbon nanotube (SWNT) material by scanning force and transmission electron microscopy, we regularly observed circular formations of SWNT ropes”. They did not even try to synthesize this tori, it just happened during the SWNT growing.
- Move Figure 7 to the same page of this part please.
6. Part 5-10, please group these parts to a bigger one such as “interaction energy of nanotorus with other nanostructures: a modelling approach” or whatever suitable to cover the topics of these specific parts. And please give an overview, or maybe a figure that illustrate these kind of interactions (including fig. 13).
- Interaction energy of atomic point and torus. What is “atomic point”, please clarify why the authors need to discuss this “atomic point” here, how it help to later on discussion or understanding.
As the modelling parts are actually results from the authors themselves and already published, I have no comments on the content.
7. Conclusions
- Again, as discussed above, considering revising the line 212-214.
- Please revise the term “nanoparticles” in line 218 (as well in the abstract part line 11) to be “nanostructures”.
Author Response
We have carefully considered all the referee’s comments and we have made changes accordingly as detailed below:
Referee 1:
1. The construction and properties of carbon nanotori have been clarified as shown in the second paragraph of the Introduction, and references [8] – [11] have also been added.
2. Four new references have been included at the beginning of Section 5 giving physical values for carbon nanotori.
3. A new figure regarding the magnetic moment and temperature of carbon nanotori has been included (Figure 15).
4. The term “nanoparticles” has been replaced by “nanostructures” throughout the manuscript.
The major changes arising from the referee’s comments have been highlighted in red in the revised manuscript.
We trust that these changes now meet with your approval.
Yours sincerely,
Duangkamon Baowan
Reviewer 2 Report
In this paper, the authors describe a theoretical study of the structure of carbon “nanotori”. The paper is clearly written and well-illustrated. I can only give a fairly superficial report on the paper, as I am not qualified to review the mathematical sections.
Comments:
On p5 the authors say “Carbon nanotori are the circular ring structures defined by two parameters describing their geometry, called major and minor radii”, but the terms “major and minor radii” have been used previously in the paper, so they should be defined earlier.
The authors discuss nanotori constructed from joining 2 nanotubes together. There have been many studies of nanotube- nanotube junctions. Should these be cited?
Units: the authors use both angstroms (e.g. p4) and nm (p5). They should be consistent – preferably use nm throughout.
There are several typos:
Line 120 “sclaed” should be “scaled”
Line 124 “fourth” should be “forth”
Line 137 “stucture” should be “structure”
Line 153 “mighe” should be “might”
Figure 5 caption. “Expertimentally” should be “Experimentally”
Ref 2: Saito, R.; Dresselhaus, G.; Dresselhaus, M. Computational Pharmaceutics: Application of Molecular Modelling in Drug Delivery; John Wiley & Sons, 2015. .............Is this right?
Author Response
We have carefully considered all the referee’s comments and we have made changes accordingly as detailed below:
Referee 2:
1. All typos have been corrected.
2. Four new references ([11] – [14]) regarding the joining of carbon nanotubes have been included in the Introduction.
3. The term Nanometer is used throughout the manuscript to be consistent.
The major changes arising from the referee’s comments have been highlighted in red in the revised manuscript.
We trust that these changes now meet with your approval.
Yours sincerely,
Duangkamon Baowan
Reviewer 3 Report
The work by Sarapat and coworkers provides an interesting exploration of the torus form of carbon. While this work provides what may be a valuable summary of the material included, I find the current manuscript to have sophomoric writing, a poor arrangement and progression, and repetitive text. It feels like a senior undergraduate literature review. While a collection of the applications and mathematics for such carbon nanotori may be useful, it does not present any new knowledge or provide a holistic review. Hence, I cannot recommend publication of this manuscript in its present form. Should the authors wish to pursue publication elsewhere, I am including below some comments which, in my opinion, would help to improve the manuscript.
The last paragraph of the introduction should be deleted. In fact, the previous two paragraphs should also be deleted as they do not provide any new references (besides the original Lennard-Jones) and are largely repeated later.
Line 120: “sclaed” should be “scaled”.
Line 153: “mighe” should be “might”.
Sections 4-10 should be subsections of a larger section called something like “Mathematical and Theoretical Framework” with each current section being a subsection.
Current section 2 should then come after this mathematical framework section before the conclusions.
The conclusions are much too repetitive of the abstract. The conclusions should tie all of the pieces of the paper together and provide some forward look. The abstract is a brief and catchy summary. While related, these two are still different sections and should be written as such.
Author Response
We have carefully considered all the referee’s comments and we have made changes accordingly as detailed below:
Referee 3:
1. The last three paragraphs in the Introduction have been rewritten in order to improve the readability of the manuscript. Also, one paragraph has been moved to be the first paragraph of Section 4.
2. Sections 4 – 10 have been changed to be Subsections 4.1 – 4.6, under Section 4: Mathematical and theoretical framework for interaction energy of nanotorus with other nanostructures.
3. The section involving “Physical roles, properties and applications” has been moved to be the last section before the Conclusions section.
4. The Conclusions section has been rewritten in order to summarize the manuscript.
The major changes arising from the referee’s comments have been highlighted in red in the revised manuscript.
We trust that these changes now meet with your approval.
Yours sincerely,
Duangkamon Baowan
Round 2
Reviewer 3 Report
The updated work by Sarapat is a marked improvement over the previous version. The updates from the authors present a clearer description of the items discussed in the manuscript. This is a good review and has a better deliverable set of items that can be gleaned by the interested reader.
