Surface-Modified Chitosan: An Adsorption Study of a “Tweezer-Like” Biopolymer with Fluorescein

Round 1

Reviewer 1 Report

This paper reviews “Surface Modified Chitosan: An Adsorption Study of a “Tweezer-Like” Biopolymer with Fluorescein” with some interesting results.

 

1.      . The authors should compare their findings with other people’s works in literature.

2.      The potential drawbacks or limitation should be addressed as well.

 

Author Response

Reviewer Report on MS ID: surfaces-569357

 

Reviewer #1

 

This paper reviews “Surface Modified Chitosan: An Adsorption Study of a “Tweezer-Like” Biopolymer with Fluorescein” with some interesting results.

 

The authors should compare their findings with other people’s works in literature.

Response:  We have compared the results at line 347 and in Table S1 of the SI.

The potential drawbacks or limitation should be addressed as well.

Response: The structural limitation is explained in line 354-355. Comparison about adsorption capacity and its lower capacity is shown by comparison with other types of pre-organized host systems in Table S1.

 

The authors wish to thank Reviewer #1 for the critical and constructive criticism on this manuscript and the opportunity to make further improvements. We have further edited the manuscript for syntax, language, and clarity throughout to meet the high standards of this journal.

 

 

 

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Adsorption of biopolymer based aniline modified chitosan with fluoroscein  is a new research.

The present study contains good results and merit to reader. Nevertheless, a major revision is required for publication in Surfaces.

Detail comments are follows:

1. Abstract: 

The authors should remove the word of Background, Results, Conclusion in Abstract.

The abbreviations need the full name for the first use in Abstract, ex: TGA, FT-IR, NMR, SEM,..

2. Introduction

- Adsorption technology should change to adsorption technique.

- For removal of contaminants by using adsorption, the authors should emphasize the advantages of adsorption comparing with other techniques.

Some papers are recommended to the authors: 

Journal of Molecular Liquids 287, 110900; Polymers 10 (2), 220;  Materials 12 (3), 450; Environmental Chemistry 14 (5), 327-337

- Chitosan is a natural polyelectrolyte that is widely used in many activities. The applications of chitosan should be introduced in more detail.

- The novelty of the present study needs indicate in Introduction.

3. Materials and Methods

- Does the synthesis of CS-Ac-An is licensed by the author. If not, appropriate reference is needed.

- It is not necessary to separate different characterization methods. 

- The authors should clarify sorption or adsorption. 

- Freundlich isotherm is well-known model but this isnot use in this work. Furthermore, two-step adsorption model is also applicable to dye adsorption.

The author should read some papers:

Polymers 10 (2), 220; Journal of Molecular Liquids 287, 110900;  Environmental Chemistry 14 (5), 327-337; Colloid and Polymer Science 293 (7), 1877-1886

- Did the adsorption experiments carry out in replicates. If yes, please show the standard deviations. If not, all results are not convincing. 

4. Results should be Results and discussion

- FT-IR spectra of CS and CS-Ac-An is not good. The y axis should change to absorbance or transmittance. 

- NMR results should add more detail and comparison. 

- The SEM images are not clear. The specific surface area is basically calculated by N2 adsorption-desorption isotherm but it is not used in this work.

- pH plays an important effect for dye adsorption that must be investigated. 

- The roles of cationic surfactants are not clear in this study. The critical micelle concentration (CMC) is important that should be discussed. 

- The regenerations should add the replicates.

- Adsorption mechanisms are not clear.  It is better to evaluate the change in surface charge after adsorption by zeta potential measurements.

5.Conclusions should be rewritten to again emphasize the originality of the present study.

Author Response

Reviewer Report on MS ID: surfaces-569357

 

Reviewer #2

Adsorption of biopolymer based aniline modified chitosan with fluoroscein is a new research.

The present study contains good results and merit to reader. Nevertheless, a major revision is required for publication in Surfaces.

Detail comments are follows:

 

 

Reviewers Comment	Author Response
The authors should remove the word of Background, Results, and Conclusion in Abstract	The recommended change was carried out.
The abbreviations need the full name for the first use in Abstract, ex: TGA, FT-IR, NMR, SEM	The recommended changes were added.
Adsorption technology should change to adsorption technique	The suggested change was made.
For removal of contaminants by using adsorption, the authors should emphasize the advantages of adsorption comparing with other techniques.	The advantages of adsorption were mentioned before with references in line 32 and 33
Some papers are recommended to the authors:  Journal of Molecular Liquids 287, 110900; Polymers 10 (2), 220;  Materials 12 (3), 450; Environmental Chemistry 14 (5), 327-337
Chitosan is a natural polyelectrolyte that is widely used in many activities. The applications of chitosan should be introduced in more detail
The novelty of the present study needs indicate in Introduction.	The novelty of the paper was discussed before in introduction section in line 66-68.
Does the synthesis of CS-Ac-An is licensed by the author. If not, appropriate reference is needed.
The authors should clarify sorption or adsorption.
Freundlich isotherm is well-known model but this is not use in this work. Furthermore, two-step adsorption model is also applicable to dye adsorption.	The Freundlich model was used in this study but it did not provide a favourable best-fit result with the experimental results. The graph and fitting parameters are shown in the SI (see Fig. S3)
Did the adsorption experiments carry out in replicates. If yes, please show the standard deviations. If not, all results are not convincing.
FT-IR spectra of CS and CS-Ac-An is not good. The y axis should change to absorbance or transmittance.	As explained in “materials and Methods” FT-IR was run in reflection mode which accounts for the greater spectral broadening. The caption has been updated to address the reviewer comments.
NMR results should add more detail and comparison.	The NMR results have been updated as suggested.
The SEM images are not clear.	Among the various SEM results collected, the images presented represent the clearest images obtained. The key features of the SEM results relate to the difference in porosity between modified and native chitosan. Further spectral interpretation is beyond the level of resolution of this technique.
pH plays an important effect for dye adsorption that must be investigated.	pH effect was studied and added to the manuscript in lines 352-354
The roles of cationic surfactants are not clear in this study. The critical micelle concentration (CMC) is important that should be discussed.
The regenerations should add the replicates.	The suggested change has been carried out.
Conclusions should be rewritten to again emphasize the originality of the present study.	The novelty is explained in lines 492-493

 

The authors wish to thank Reviewer #2 for the critical and constructive criticism on this manuscript and the opportunity to make further improvements. We have further edited the manuscript for syntax, language, and clarity throughout to meet the high standards of this journal.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The revised manuscript was revised by the authors.

The authors also response to my comments.

However, many points were not addressed. 

Too many references were cited.

But the appropriate ones were not referenced.

The authors must read the recommended papers:

Journal of Molecular Liquids 287, 110900; Polymers 10 (2), 220;  Materials 12 (3), 450; Environmental Chemistry 14 (5), 327-337