Side-Chain Liquid Crystal Co-Polymers for Angular Photochromic Anti-Counterfeiting Powder and Fiber

Round 1

Reviewer 1 Report

The manuscript entitled "Side-chain Liquid Crystal Polymers for Angular Photochromic Anti-Counterfeiting Powder and Fiber" is an experimental work. The topic of the manuscript fits well the scope of the journal. The results are novel and should have definite impact on the specific field of research. Several issues should be addressed by the authors before the manuscript can be accepted for publication. Here are the specific comments: 

(A) It is not sufficiently clear if authors synthesize the monomers (both the nematic and cholesteric ones) and the resulting side-chain polymers  or this is a commercial materials. Anyway, the appropriate references are missing.

(B) The description of the samples/cells used for the observations in POM and for DSC is missing.

(C) Language corrections by the native speaker are required.

(D) The requirement for the  LC materials suitable for anti-counterfeiting films is not clearly formulated. It would be very advantageous if authors will explicitly add those requirements to the introduction section.

(E) To be absolutely correct, authors should use the term <liquid crystal co-polymers> instead of used <liquid crystal polymers>. Please consider to revise.

Author Response

Response to Reviewer 1 Comments

Point 1: The manuscript entitled "Side-chain Liquid Crystal Polymers for Angular Photochromic Anti-Counterfeiting Powder and Fiber" is an experimental work. The topic of the manuscript fits well the scope of the journal. The results are novel and should have definite impact on the specific field of research. Several issues should be addressed by the authors before the manuscript can be accepted for publication. Here are the specific comments:

(A) It is not sufficiently clear if authors synthesize the monomers (both the nematic and cholesteric ones) and the resulting side-chain polymers or this is a commercial material. Anyway, the appropriate references are missing.

 

Response 1: Thanks for the reviewer’s dealing with the paper and for the kindly remind. The monomers and polymers were synthesized in the lab and information about it has been add in the paper Line 227-228.

 

Point 2: (B) The description of the samples/cells used for the observations in POM and for DSC is missing.

 

Response 2: Thanks very much for the reviewer’s kindly remind. Information about the tested samples has been add in Line 111-112 and 128-129.

 

Point 3: (C) Language corrections by the native speaker are required.

 

Response 3: Thanks very much for the reviewer’s precious advice. Corrections have been made and noted using the "Track Changes" function.

 

Point 4: (D) The requirement for the  LC materials suitable for anti-counterfeiting films is not clearly formulated. It would be very advantageous if authors will explicitly add those requirements to the introduction section.

 

Response 4: Thanks very much for the reviewer’s precious advice. The requirements for the  LC materials has been add in Line 85-86.

 

Point 5: (E) To be absolutely correct, authors should use the term <liquid crystal co-polymers> instead of used <liquid crystal polymers>. Please consider to revise.

 

Response 5: Thanks very much for the reviewer’s kindly remind. Corrections have been made in Line 2, 14, 25, 71, 105, 186 and 199.

Author Response File: Author Response.docx

Reviewer 2 Report

The authors submitted the article entitled “Side-chain Liquid Crystal Polymers for Angular Photochromic Anti-Counterfeiting Powder and Fiber”. In this manuscript, the authors prepared side-chain liquid crystal copolymers and polymer blends with different ratios of cholesteric mesogens for the application in anti-counterfeiting materials. The motivation of the research is clear and there are some promising results for the final application, however, the reason for selecting polymer design is not well described. I would recommend the paper could be accepted after minor revision. My main comments and questions are as follows:

The chemical structure of the polymer including side chain cholesteric mesogens should be presented in Figure 1a. The POM images of copolymers at different temperature during heating/cooling experiments are necessary to support the description of Page 3, line 116. Author prepared polymer blends of HG1-3 from two different copolymers for the comparison of polymer materials with different ratio of cholesteric mesogens. It should be also possible to parepare copolymers containing similar ratio of cholesteric side-chains. Are there any difference between polymer blends and copolymers in thermal, optical or mechanical properties? The authors mentioned about the mechanical property of the polymers in Page 6, Line 178. The mechanical tests of the polymer films are recommended. English correction by native speaker is highly recommended.

Author Response

Response to Reviewer 2 Comments

Point 1: The authors submitted the article entitled “Side-chain Liquid Crystal Polymers for Angular Photochromic Anti-Counterfeiting Powder and Fiber”. In this manuscript, the authors prepared side-chain liquid crystal copolymers and polymer blends with different ratios of cholesteric mesogens for the application in anti-counterfeiting materials. The motivation of the research is clear and there are some promising results for the final application, however, the reason for selecting polymer design is not well described. I would recommend the paper could be accepted after minor revision. My main comments and questions are as follows:

The chemical structure of the polymer including side chain cholesteric mesogens should be presented in Figure 1a.

 

Response 1: Thanks for the reviewer’s dealing with the paper and the kindly remind. Figure 1a has been revised to show the chemical structure of the polymer and the cholesteric mesogen.

 

Point 2: The POM images of copolymers at different temperature during heating/cooling experiments are necessary to support the description of Page 3, line 116.

 

Response 2: Thanks very much for the reviewer’s precious advice. A figure (Figure 2 in the paper) has been added to show the POM images of the sample at different temperatures during heating and cooling process.

 

Point 3: Author prepared polymer blends of HG1-3 from two different copolymers for the comparison of polymer materials with different ratio of cholesteric mesogens. It should be also possible to prepare copolymers containing similar ratio of cholesteric side-chains. Are there any difference between polymer blends and copolymers in thermal, optical or mechanical properties?

 

Response 3: Thanks very much for the question. By use the blending method, the manufacturing process could be simplified which is an advantage for the practical application. It is a good idea to compare the properties of polymers prepared through blending and chemical synthesize and the author is going to continue the further research.

 

Point 4: The authors mentioned about the mechanical property of the polymers in Page 6, Line 178. The mechanical tests of the polymer films are recommended. English correction by native speaker is highly recommended.

 

Response 4: Thanks very much for the precious advice. The side-chain liquid crystal polymers have the mechanical property of polymers and could be made in to powders and fibers. The authors are going to conduct experiments about the processability of the materials including the mechanical characterization. Corrections have been made and noted using the "Track Changes" function.

 

Author Response File: Author Response.docx

Reviewer 3 Report

The Authors present a series of side-chain liquid crystal polymers with different center reflection wavelengths in visible and near IR region. The Authors did DSC, polarized OM measurements and SEM of the surface of the LCP. The possible applications of these blends of SCLCPs could be anti-counterfeiting powders.

I think that general idea and measurements are interesting, but the Article should be rejected from journal Crystals. The materials and the possible applications suggest that it should be sent to the journal more related with liquid crystals and/or polymers (e.g. Molecular Crystals Liquid Crystals) or to the journal related to forensic science.

Author Response

Response to Reviewer 3 Comments

Point 1: The Authors present a series of side-chain liquid crystal polymers with different center reflection wavelengths in visible and near IR region. The Authors did DSC, polarized OM measurements and SEM of the surface of the LCP. The possible applications of these blends of SCLCPs could be anti-counterfeiting powders. I think that general idea and measurements are interesting, but the Article should be rejected from journal Crystals. The materials and the possible applications suggest that it should be sent to the journal more related with liquid crystals and/or polymers (e.g. Molecular Crystals Liquid Crystals) or to the journal related to forensic science.

 

Response 1: Thanks for the reviewer’s dealing with the paper and the precious advice. The paper is about liquid crystal material and its application. The journal has four sections including Liquid Crystal and the theme of the article is suitable for the journal.

Author Response File: Author Response.docx