Poly (Vinylidene Difluoride) Polymer in 1-Ethyl-3-methylimidazolium Acetate and Acetic Acid Containing Solvents: Tunable and Recoverable Solvent Media to Induce Crystalline Phase Transition and Porosity

Round 1

Reviewer 1 Report

I have received the Manuscript (ID: suschem-1958352) entitled: ‘Poly (vinylidene difluoride) polymer in 1-Ethyl-3-methylimidazolium acetate and acetic acid containing solvents: Tunable and recoverable solvent media to induce crystalline phase transition and porosity’ submitted to the MDPI Sustainable Chemistry for a review.

In the following research 1-ethyl-3-methylimidazolium acetate (IL), acetic acid (AA) and their mixtures were applied for the thermal processing of crystalline polymer - poly(vinylidene difluoride), PVDF. The authors established that upon IL and AA combined solvent treatment, the neat PVDF which composed of both α- and β crystalline phases was transformed to porous and β-phase rich material, whereas in case of pure AA the nonporous and pure α-phase polymeric entity was obtained.

 In this Manuscript authors demonstrated very good skills in the characterization of the processed material. The methodology contains sufficient data and demonstrates authors excellent skills in the field of materials science. The discussion in the paper are well-founded and all references are well presented. Therefore, I consider the submitted Manuscript as a very good candidate for publication in Sustainable Chemistry. However, in the revision process I recommend to improve the following errors/ ambiguities:

1.     Line 2: the authors should be consistent with the spelling of the utilized polymer, e.g. in the title there is "poly (..." and here "poly-(...". Additionally, “ethyl…” should start from small letter

2.     Line 142: “ethyl…” should start from small letter

3.     Line 245-246: this explanation is not sufficient and fully correct. The authors should refer to the concept of oligomeric anions in ILs described by Seddon and MacFarlane - Phys. Chem. Chem. Phys., 2008,10, 2972-2978.

4.     Line 625-626: abbreviations should be explained below the table

5.     Lines 631-632: what about the ratio between the integration of signals originating from IL and AA? IL is non-volatile, however, traces of AA can be evaporated with acetone, and the recovered AA in mixture may need replenishment. Therefore, there should be a clear information regarding that issue

6.     Lines: 758-771: this part should appear between conclusions and references

Author Response

We would like to thank to Reviewer for reviewing the manuscript carefully and providing the valuable inputs to improve the content in the manuscript. Please see the attachment for the response to the reviewer's comments. 

Author Response File: Author Response.docx

Reviewer 2 Report

Khokarale and co-workers reported resistance properties of poly(vinylidene difluoride polymer (PVDF) against treatment with ethylmethylimidazolium acetate ([Emim)[AcO]) and acetic acid. I feel that the final goal of the present study is to achieving recycle of PVDF. Unfortunately, this aim was not completed. Furthermore, the IL treatment process might be difficult to exploit for industrial scale as the authors mentioned in the conclusion part. However, the results might be dependent on the appropriate choice of ILs. Why the authors choose [Emim][OAc] as possible solvent for PVDF among numerous types of ILs? The authors should mention the reason why they selected this IL for this study in the text. Anyhow, since the authors very carefully investigated this work, this reviewer feels that the work may be worth for publication on this journal after an appropriate revision. My concerns are as follows: Page 7, line 282: Reference [37] should be revised. Although this paper [37] reports only the possible application of PVDF as printable piezoelectric devices, neither the Kamlet-Taft parameters nor Reichardt’s dye is reported. I recommend that the authors should cite original papers for the Kamlet-Taft parameter as follows: a) M. J. Kamlet, R. W. Taft, J. Am. Chem. Soc. 1976, 98, 377. b) T. Yokoyama, R. W. Taft, M. J. Kamlet, J. Am. Chem. Soc.1976, 98, 3233. c) R. W. Taft, M. J. Kamlet, J. Am. Chem. Soc.1976, 98, 2886. d) M. J. Kamlet, J. L. Abboud, R. W. Taft, J. Am.Chem. Soc. 1977, 99, 6027.

Author Response

We would like to thank to Reviewer for reviewing the manuscript and providing the relevant comments to improve the content in the manuscript. Please see the attachment for the response to the reviewer's comments. 

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The authors revised the manuscript according to the suggestions by reviewers. The quality of the manuscript has been improved well. Therefore, I recommend that the work should be published on Sustainable Chemistryas this form.