Coating Mechanism of AuNPs onto Sepiolite by Experimental Research and MD Simulation

Round 1

Reviewer 1 Report

The manuscript focus on preparationa and charakteristic of AuNPs-sepiolite material. The results are original, however, some improvements in the text are needed.

1. The abstract and introduction contain unexplained abbreviations (like MD and DFT), which should be described at the first appearance. 

2. line 48-51: the references of cited research are lacking.

3. The aim of the study (research hypothesis) is unclear. Moreover, the potential applications of tested material are not mentioned directly.

4. In the introduction and conclusions the Authors should justify and underline the scientific significance of research, its importance and novelty.

5. line 88: The SI unit should be used instead 'cc'.

6. Fig. 2: the solid line in graph may be misleading, because the measurement was not carried out in continues pH change mode. I suggest dashed line as more appropriated.

7. Fig. 3: Column labels are difficult to read. Moreover, the MS and NS abbr. are not explained.

8. There is no results discussion in the section 'Zeta potential'.

9. line 193-195: Could the Authors justified the last sentence in the chapter?

10. line 204: What kind of 'carbonates impurities' are expected?

11. line 361: How can be 'bio-compatibility' justified?

Author Response

Dear Ms. Verna Yu, Assistant Editor of Journal of Coatings,

The authors would like to thank you and all of the reviewers for their valuable contributions to increase the quality of the paper. Please kindly find to the responses and information about the changes been made throughout the paper. The necessary corrections and modifications have been highlighted in green colour for Reviewer 1. Additionally, the removed texts were marked with a strikethrough font in red color.

Best regards,

Assoc. Prof. Orhan OZDEMIR

Author Response File: Author Response.pdf

Reviewer 2 Report

Tha paper is too rough to be correctly considered, and is not publishable in this form

1. The main problem: which is the sense in comparing the xeperimental results in which AuNPs of 15-30 nm diameter are observed, with MD calculations in which AuNP made of a few atoms and diameter < of 1 nm are considered? calculations may be right and/or interesting, but the situation is completely different from the experimetal data, so, which is the point of this investigation?

In the introduction  authors state that "In this study,
adsorption and coating of AuNPs to the basal surface of the sepiolite in the absence/presence of hexadecyltrimethylammonium bromide (HTAB) was experimentally investigated and supported with Molecular Dynamics (MD) simulations." but this in my opinion is not true, as MD calculations made on 24 atoms AuNP cannot sustain the intrepretaion of a phenomena involving AuNP which are really bigger!

other points:

2. in the experimental part, it is stated that "The AuNPs were produced in two samples, 1 and 25 ppm, until their size reached purplish color (averagely sized 150 nm) using the procedure of Frens[36]." while the mean dimension of AuNP is found to be about 15 nm...

3. figure 2 caption is wrong, it should say that dependance of z potential is related to pH changes

4. I cannot understand then differences between figure 3a and 3c (identical) and the differences between figures 3b and 3d (identical as well). The discussion related to this figure is not understandable.

5. the statement "Meanwhile, the suspension color changed from red to blue with increasing amine concentration indicating the increase in the size of gold nanoparticles." should be coroborated by some spectra.

Anyway, a change in colour from red to blue denounces some seriuos growth or agglomeration, this should be clarified! it is not clear to me when this colour change happens: authors are increasing  the concentration of which amine? and why?

6. hexadecyltrimethylammonium bromide is universally known as CTAB, why here is called HTAB?

7. English should be checked, as many passages are hardly readable

Author Response

Dear Ms. Verna Yu, Assistant Editor of Journal of Coatings,

The authors would like to thank you and all of the reviewers for their valuable contributions to increase the quality of the paper. Please kindly find to the responses and information about the changes been made throughout the paper. The necessary corrections and modifications have been highlighted in yellow colour for Reviewer 2. Additionally, the removed texts were marked with a strikethrough font in red color.

Best regards,

Assoc. Prof. Orhan OZDEMIR

Author Response File: Author Response.pdf