Experimental Study on Van der Waals Interactions Between Organic Groups of Quaternary Ammonium Salt Surfactants and Montmorillonite in Aqueous Solutions
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsIn this manuscript, the authors investigated the dipole interaction between the hydrophilic end of quaternary ammonium surfactants (QASs) and montmorillonite (Mnt) in aqueous solutions based on experimental results. In this study, the average adsorption distance, Van der Waals (VDW) adsorption energy and VDW constant of QASs and its groups adsorbed on the montmorillonite surface is obtained by microcalorimeter. The topic is interesting and unique, and the methodological approach seems solid and appropriate. The study will be prospective and contributes for the field of material science including adsorption engineering. There is basically no problem regarding English. Therefore, I feel this paper should be acceptable after some revisions in view of the following comments.
(1) How many replicates do the experimental data represent? There are no errors for data presented in Tables 1-5. Please show experimental errors (i.e., standard deviation) for measurement results. Regarding Figures (e.g., Figures 6 and 7), please show experimental errors (i.e., error bars) for measurement results, if possible.
(2) In this study, five QASs (DTAC, CTAC, STAC, HDBAC, and CPC) were selected. Please explain the reason of selection.
(3) Regarding the experiment methods (2.2), it would be better and comprehensive if the authors use figures including the flow chart of experimental procedure and/or experimental device or equipment.
(4) In conclusion, it would be interesting if the authors could mention the study implications, applications or recommendations for now and the future.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors presented experimental data on the study of van der Waals interactions between organic groups of quaternary ammonium salts in surfactants and montmorillonite. The study is probably important, but the reviewer did not find either the purpose or the novelty and importance of the work. In the presented form, the work is difficult to perceive and it is difficult to understand the authors' idea.
1) Page 2, line 57: Despite the fact that in the Abstract the authors provided a transcript of QASs, this is the first time this has occurred in the text of the manuscript.
2) What means DTAC, CTAC, STAC, HDBAC and CPC, ESEM, FBRM? The reviewer did not find a transcript in the further text.
3) From the Introduction it is not clear what the purpose of the presented work is and its novelty.
4) What data are obtained from the results of light transmittance measurements at 930 m?
5) What device was used to measure the ESEM? And how were the montmorillonite suspension samples prepared?
6) For what reason do the authors provide a breakdown of the abbreviation BTB on page 9?
7) page 6 line 211: Did the authors actually conduct TG-DSC tests on the water?
8) To equations (2) and (3): What are R1, R2, D, Ead, Fad, g, mas?
9) Fig. 2-6, 8 present data for only three (!) surfactants. Section 2 claims 5! Where is the data for the other?
10) Why do the authors register transmission at only one wavelength? What does the entire absorption spectrum of the suspensions look like?
11) Page 10: For what reason do the authors repeat the data presented in tables 2-5 in the text?
12) In the opinion of the reviewer, it would be more convenient to present subsection 3.3.3 as a table with formulas of chemical endings of surfactants, constants, and calculated values ​​and accompanying text. It would also be useful to know the discussion of the obtained results and not just a statement of data.
The comments provided do not reduce the level of the work but will help to understand the idea of ​​the authors and the purpose of the research.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors have taken into account all the reviewer's comments. Thanks.
