pH-Responsive Eco-Friendly Chitosan–Chlorella Hydrogel Beads for Water Retention and Controlled Release of Humic Acid

Round 1

Reviewer 1 Report

Your manuscript in an overall look does not suffer scientifically. You should correct syntax-grammar errors in the appropriate yellow marked points in the attached file.

You should scrutinize your references as to completely comply to the MDPI form and style. 

Comments for author File: Comments.pdf

Author Response

Response to Reviewer 1 Comments

 

Comments and Suggestions for Authors:

 

Your manuscript in an overall look does not suffer scientifically. You should correct syntax-grammar errors in the appropriate yellow marked points in the attached file.

You should scrutinize your references as to completely comply to the MDPI form and style.

 

Response:

Thank you for your suggestions and modifications. According to your suggestion, we have corrected the spelling and grammar errors and improved the quality and clarity of the language throughout the whole manuscript. Changes that have been made to the manuscript are marked in red.

We have strictly revised the format of references to ensure that they meet the requirements of MDPI.

Author Response File: Author Response.docx

Reviewer 2 Report

Review: In my opinion, the article is almost ready for acceptance in present form. There are only minor errors. But I find one important thing - in some graphs I lack standard deviations of measurements, or information about the accuracy of the obtained data (in graph or text). If data is obtained, I recommend adding this information to the graphs or text. 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

The manuscript submitted by authors related to pH-responsive eco-friendly chitosan-chlorella hydrogel beads for water retention and controlled release of humic acid is a very interesting work and fully in the scope of the Journal.

But, still manuscript lack in several ways. The manuscript can be accepted for publication after revision.

1. Kindly provide the strong reason behind choosing Chlorella is a spherical, unicellular microalga which is bio-based filler that were selected to enhance the mechanical strength of the hydrogels. Why not any other bio filler?
2. Will any filler can be added with chitosan? Any special requirement during the selection of filler with biopolymer?
3. Kindly discuss more on the structure and composition of chitosan and chlorella.
4. How does the molecular weight of chitosan impact its application?
5. In the introduction, you need to connect the state of the art to your paper goals. Please follow the literature review with a clear and concise state of the art analysis. This should clearly show the knowledge gaps identified and link them to your paper goals.
6. Please reason both the novelty and the relevance of your paper goals.
7. Clearly discuss the previous studies that you are referring to.
8. What are the Research Gaps/Contributions? Please note that the paper may not be considered further without a clear research gap and novelty of the study.
9. Section 2.1. Experimental Materials, provide the grade and purity of chemicals used in this work.
10. The authors should mention “Polymer has proven to be an effective prolonged-release carrier”. And Kindly provide the relevant references to support the statements. [Journal of Molecular Liquids 345, 117028, 2022; Journal of Molecular Liquids 346, 118271, 2022]
11. Section 2.2. Synthesis of Chitosan–Chlorella Hydrogel Beads, is its author's own protocol or adopted from literature.
12. If author own? Kindly provide the optimization study for the synthesis of Chitosan–Chlorella Hydrogel Beads.
13. Figure 3(e, f) were the surface microtopography images of chitosan hydrogel beads and chitosan-chlorella hydrogel beads, respectively. Kindly provide the clear scale bar in the SEM images.
14. Authors have mentioned “In other words, the presence of chlorella enhanced the mechanical stability of hydrogel beads. The cross-linking between chlorella and chitosan three-dimensional network has strong hydrogen bonding interactions, while the hydrogen bonding as crack bridges maintained intact structure and stable centrifugal deformation, endowed the chitosan-chlorella hydrogel beads with good compressive properties” Kindly justify this statement by providing appropriate references.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

The authors have not seriously amended most of the comments provided by reviewer.

Author Response

Please see the attachment.

We appreciate for your warm work earnestly, and hope that the correction will meet with approval.

Author Response File: Author Response.docx

Round 3

Reviewer 3 Report

The authors have revised the manuscript.