Luminescent Properties of Polycarbonate Methacrylates Containing Organic Fluorescent Dyad

Round 1

Reviewer 1 Report

This manuscript is very similar to the previous article reported by the authors in Dyes and Pigment journal (see Ref#17). The research design is not appropriate and the aims and novelty of this manuscript are ambiguous. The significance and superiority of current results over previous reports are not highlighted in the text. In addition, there is no experimental methods and characterization techniques for the prepared oligocarbonate methacrylates and their polymers. Therefore, I think the originality and significance of this work is not sufficient to be published in the journal of “Coating”.

There are some typos and grammatical mistakes in the manuscript which need to be refined thoroughly.

Author Response

We are very thankful to reviewers for their careful analysis of our work. Their comments were very helpful and permit us to improve the paper. We have done major revision of the paper (highlighted yellow) according to these remarks and hope that it improved the manuscript quality essentially. 

The reviewer proposed to improve the overall presentation of the manuscript. In accordance with the comment of the reviewer the text of the article has been rewritten and improved for better understanding, especially in the sections “Introduction” and “Materials and methods”.

In Introduction we have indicated in detail in which polymers the properties of the dyad were studied earlier and formulated the purpose of this study:  “It was shown that this compound is characterized by dual fluorescence with maxima at 430 - 450 and 530 nm, the ratio between them depends on the solvent nature and the excitation wavelength. The study of the dyad’s luminescence in the matrices of linear polyoligoester acrylates with different number of hydroxyl groups [19] demonstrated that the presence of hydroxyl in the polymer matrix has a moderate effect on the relative   intensities of two fluorescence bands. The reason of this effect is hydrogen bonds formation between dyad molecule and polymer.” ….

“So the aim of this study is to elucidate the influence of the polymer matrices structure and morphology within other class of polymers without hydroxyl groups on the luminescent properties of the dyad in order to find more pronounced effect.” 2. Section “Materials and methods” was improved. Experimental methods for OCM synthesis and their polymers preparation are included.

Reviewer 2 Report

The authors in this paper show the luminescent properties of Polycarbonate Methacrylates containing organic fluorescent dyad. They show the presence of two emission bands whose intensities change with different excitation wavelengths and the nature of the polymer matrix. The paper is well written but in my opinion it needs to be still improved before publication.

1)  The authors show the chemical formula of the polymers of oligocarbonate methacrylates studied. Can they draw the different chemical compounds? it is easier for a no-chemist to see the differences between them.

2) In table 1 what is the acronym MM? how was detected the fluorescence ?  is it possible to do a PL quantum yield measurement? It will be nice to see if also the overall luminescence is different in all the polymers studied.

Author Response

We are very thankful to reviewers for their careful analysis of our work. Their comments were very helpful and permit us to improve the paper. We have done major revision of the paper (highlighted yellow) according to these remarks and hope that it improved the manuscript quality essentially.

1. We have drawn separate chemical formulas of all oligocarbonate methacrylates studied for better understanding of the difference in their structure.
2. Table 1 was significantly changes. Acronym Mm was changed on MW, it represents molecular weights of obtained polymers. It was explained in the Chapter “Materials and methods”.

 Fluorescence measurements are described in the section “Materials and methods”. Relative quantum yields have been determined and given in the text of the article. They were of the same order of magnitude and don’t depend on the matrix nature. The measurements of real quantum yields demand preparation of the “blank” samples (without dyad) of all polymers having the same thickness and size as that studied in this work. This is not an easy task because the studied films were quite thin and fragile.

The difference in fluorescence in the polymers studied is shown in Figure 7.

Reviewer 3 Report

   In this manuscript, the authors studied the luminescence properties of organic fluorescent dyad with photosensitive fragments, namely, tetraarylimidazole with a hydroxy group and azomethinocoumarin, doped into aliphatic and aromatic network polycarbonate methacrylates. The results showed that two emission bands can be adjusted either by the excitation wavelength or by the oligomeric bridges (length, flexibility, and polarity). As only the emission spectra are measured, the authors should do more characterizations for these materials.

1. What are the quantum yields for these luminescent materials?

2. Photo-stability tests should be performed.

3. In Table 1, for the spectra of samples OCM-1 and OCM2/1 excited at 330 nm, if spectral deconvolutions are made, we can se two bands. 

4. Some typos or errors: 

4.1 Page 2, “methile chloride”: used the correct name.

4.2 Page 3, “подсоединение в мета-положение#”: use English.

4.3 Page 3, “Fluorescence intensity,,”: delete one “,”.

4.4   In the References part, there are many errors related to space, capitalization of the letters, and punctuation mark. I mention some of them: 

Ye.S.   Sci.A.

Journal of macromolecular science – chemistry,   Scientific reports,

S.H.,; D.J..; B.W.,; 1995.,

Moderate editing of English language are needed.

Author Response

We are very thankful to reviewers for their careful analysis of our work. Their comments were very helpful and permit us to improve the paper. We have done major revision of the paper (highlighted yellow) according to these remarks and hope that it improved the manuscript quality essentially.

1. Relative quantum yields have been determined and given in the text of the article. They were of the same order of magnitude and don’t depend on the matrix nature. The measurements of real quantum yields demand preparation of the “blank” samples (without dyad) of all polymers having the same thickness and size as that studied in this work. This is not an easy task because the studied films were quite thin and fragile.
2. Photo-stability test was performed for OCM-2 polymer film containing fluorescent dyad and its results are given on the page 5 of the text: “Photo-stability test was carried out for the dyad in the polymer matrix obtained from OCM - 2 when irradiated with a halogen lamp with an intensity of 50 w/m² through a SS–4 light filter (transmission range 340 - 470 nm) at a distance of .15 cm during 5 hours. No changes were obtained in the absorption spectra during this time.”
3. Table 1 was significantly changed, now it presents a ratio of fluorescence band intensities with maxima at 450 nm and 535 nm at different λ_ex (330 nm and 350 nm).
4. All mistakes in the text were corrected.
5. Errors in the references part were corrected.
6. Moderate editing of English was made with participation of a native English.

Round 2

Reviewer 1 Report

The authors have addressed the referees’ comments and the manuscript has been sufficiently improved to warrant publication in Coatings.

Author Response

We are very thankful to Academic Editor  and reviewers for their careful analysis of our work. Their comments were very helpful and permit us to improve the paper. We have done revision of the paper according to these remarks and hope that it improved the manuscript quality essentially (marked green).

The minor corrextion and editing was nade.

Reviewer 3 Report

The authors answered and/or corrected the items for my concerns. The paper can be accepted in present form. However, the authors should correct some typos or style errors in the manuscript, such as:

1. The unit for the temperature should be used the same style.

2. Typo: "are normalized to 450 nm bond" should be "are normalized to 450 nm band".

3. Sentence: “under short wavelength excitation (330 - 340 nm)” should be “under short wavelength (330 - 340 nm) excitation” or “under short excitation wavelength (330 - 340 nm)”.

4. The style for the journal name in the references should be the same format.

Minor editing of English language is required

Author Response

We are very thankful to Academic Editor  and reviewers for their careful analysis of our work. Their comments were very helpful and permit us to improve the paper. We have done revision of the paper according to these remarks and hope that it improved the manuscript quality essentially (marked green).

1. The unit for the temperature is made in the same style (page 4).
2. The sentence "are normalized to 450 nm bond" has been replaced with "are normalized to 450 nm band”. (page 6).
3. The sentence “under short wavelength excitation (330 - 340 nm)” has been replaced with “under short wavelength (330 - 340 nm) excitation” (page 6).
4. The style for the journal names in the references was made in the same format.

Minor editing of English language was made.