Dielectric Spectroscopy: Yesterday, Today and Tomorrow

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This perspective paper provides a brief outline of some aspects of the history of dielectric relaxation studies, emphasizing the advances made in the last 100 years. On the other hand, the know shortfall of this technique is its lack of molecular details in regard to dipole moment contributions and dynamics. The paper discusses an avenue to more detailed and more microscopic information by combining dielectric spectroscopy with IR absorption experiments. While this will not become a routing experiment in the near future, it is still useful to emphasize what ordinary dielectric relaxation results are missing and ow to possibly overcome the issues. I recommend publication of this work in MDPI's journal Applied Sciences in its present form.

Author Response

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Reviewer 2 Report

Comments and Suggestions for Authors

The authors has reviewed the limitation of current analysis of BDS based on Debye method, which combining OPS method may overcome such limitation. The authors used polyalcohol system to explain the application of classical theory and the inconsistency between models and experiments. The reviewer only has minor recommendation to briefly mentions some systems with intra-intermolecular interaction other than hydrogen bond, which shows above-mentioned inconsistency as well. 

Author Response

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Reviewer 3 Report

Comments and Suggestions for Authors

Review of the manuscript “Dielectric Spectroscopy: Yesterday, Today and Tomorrow” by Friedrich Kremer and Martin Tress.

 

The manuscript is interesting for scholars and contributes to reflection on this topic.

 

Notes on the manuscript.

1. There is no reference to Table 2 at the beginning of the manuscript, or maybe line 63 should read Tab. 2?
2. There is no blank line between the caption for Figure 2 and the following paragraph. The same remark applies to Figure 3 and other figures.
3. In modern physics, it is accepted that for absorbing media the imaginary part of the dielectric constant is positive, accordingly, formula (7) should have a “+” sign.
4. It says in the line “Combining eq. 14 and 12 yields”, it should probably be “Combining eq. 11 and 12 yields”.
5. It seems that one term is missing in formula (14), if it is neglected, then why?6.
6. There is no explanation of the letter designations of physical quantities in some formulas.
7. It is not entirely clear whether the figures were obtained by the authors or borrowed from other authors. If borrowed, then make a reference in the captions to the figures.

 

I recommend that the authors of the manuscript reread the manuscript to improve its structure and clarify unclear statements.

 

Conclusion. The manuscript can be published taking into account the comments.

Author Response

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Reviewer 4 Report

Comments and Suggestions for Authors

This manuscript is a valuable contribution to the field of dielectric spectroscopy and molecular dynamics studies. The authors present the basis in Debye theory, modern capabilities of broadband dielectric spectroscopy, and future directions of development through the new method of orientational polarization spectroscopy (OPS). The manuscript is timely and addresses the growing interest in linking macroscopic dielectric responses with inter- and intra-molecular dynamics, particularly in complex systems.

The authors should revise the manuscript considering the minor comments as follows:

1) As a perspective article, the discussion should be strengthened by outlining more concrete directions for future studies.

2) In Figure 3,  the relaxation times and relaxation strength are shown for the β-relaxation process. However, neither the figure caption nor the main text clearly explains or defines this process.

3) There is a missing unit of angular frequency in Figure 5.

4) Line 221: Eq. 13 is the combination of Eq. 11 and 12, not Eq. 14 and 12.

5) Line 88: Please repair the typographic error in vacuum permittivity.

6) The authors should appropriately describe the equations; for example, line 191: ε∞ (and εS) should be introduced earlier for the equation in line 98.

Author Response

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