Effect of the Solvent Type on the Colloidal Stability and the Degree of Condensation of Silica Sols Stabilized by Amphiphilic Urethane Acrylate and the Properties of Their Coating Films

Round 1

Reviewer 1 Report

This is a valuable work that allows to substantially improve the technological process. 

Some additional characterization of the silica sols can be shown, namely, the PDI values and the uncertainty of the size values. The size of particles is presented in Table 2 with excessive digits. 

The results are really impressive; however, only four solvents are discussed. It would be interesting to know if some other solvents were used, maybe, in some preliminary experiments?! 

Author Response

Thank you for reviewing our manuscript. We appreciate your time and valuable comments, which have acknowledged the strengths of our research and provided valuable feedback. Based on your comments and suggestions, we have made the necessary modifications to our manuscript. Please find detailed responses, highlighted corrections, and supplementary data in the attachment file, including the responses to the reviewer's comments and the list of modifications.

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript “Effect of the solvent type on the properties of colloidal silica sols prepared in the presence of amphiphilic urethane acrylate and the properties of their coating films” focuses on characterizing properties of organic-inorganic silica hybrid sols, which are used for formation of coatings with the application in automotive industry.

The manuscript represents a research work, which provides a correlation of fundamental aspects of colloid chemistry and interfacial phenomena, such as intermolecular interactions, with properties of resulting colloidal systems and the respective impact on performance of coatings.

The authors discuss in detail the impact of solvent properties in sizes and stability of colloidal particles based on organic-inorganic hybrids and the resulting performance of coating materials.

It is of particular interest that the authors discuss properties of colloidal systems by prioritizing solvent influence, which is definitely worth of a strong focus in chemistry of supramolecular systems, colloid systems, and soft matter.

The manuscript fits the scope of “Coatings” and the section selected for its submission.

The manuscript can be considered for publication provided that the following questions and issues are addressed:

1. Particle size in Fig. 2 – is it radius or diameter? Also, DLS does not provide the accuracy of fractions of a nanometer. Approximate values (nanometer range) should be given. Also, error bars or standard deviation values for size data to evaluate if the difference between values for P and C solvents is not within the experimental error.

2. The same recommendation is to approximate too accurate DLS size values in the rest of the manuscript.

3. What was the PDI value of particles evaluated by DLS?

4. For P and C solvents, the difference in the dielectric constant is much larger than in respective sizes of particles (which virtually do not change). In the text, however, the authors explain size differences by changes in solvent properties and we can expect a much larger difference in sizes of particles. Please comment.

5. Did the authors evaluate adhesion of coatings to the glass substrate? How can you comment on a possible impact of solvent on adhesion of coatings?

6. Readability of long paragraphs (such as that in Lines 25-59) should be considered. The authors are recommended to split long paragraphs for better readability.

7. Conclusion is recommended to briefly enrich with more specific details about impact of each solvent on performance of coatings.

Author Response

Thank you for reviewing our manuscript. We appreciate your time and valuable comments, which have acknowledged the strengths of our research and provided valuable feedback. Based on your comments and suggestions, we have made the necessary modifications to our manuscript. Please find detailed responses, highlighted corrections, and supplementary data in the attachment file, including the responses to the reviewer's comments and the list of modifications.

Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript presents an interesting topic on the effect of the solvent type on the colloidal stability and degree of condensation of silica sols.

A few comments and questions are due before we proceed with this submission:

1-title is too general. add the words "stability" and "condensation" of the coating in the title.

2-the formation of a homogeneous film upon curing, resulting in increased mechanical properties of the coating film. is this correlating with the sem images in fig. 7? do you see any indication of the strengthened mechanical properties? can you correlate the SEM to mechanically increased properties?

3-In the introduction, the citation is essential to:https://doi.org/10.1016/j.rinp.2021.104804

4-what was the impact of your proposed approach to provide the needed ions on the medium condition to improve the reaction rate? is there any indication of that in TGA results too? any change of TGA curve by improved reaction rate?

When authors take my comments in and reply to my questions above and revise the manuscript accordingly, i can reconsider my decision. do not skip any comments above.

Author Response

Thank you for reviewing our manuscript. We appreciate your time and valuable comments, which have acknowledged the strengths of our research and provided valuable feedback. Based on your comments and suggestions, we have made the necessary modifications to our manuscript. Please find detailed responses, highlighted corrections, and supplementary data in the attachment file, including the responses to the reviewer's comments and the list of modifications.

Author Response File: Author Response.pdf