Chitosan-Based Composites for Sustainable Textile Production: Applications Across the Lifecycle

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Line 44: It would be beneficial for the reader to see the structure of Chitosn and the derivation from chitin. It can also help support lines 260, where the N-acetylglucosamine and glucosamine groups are mentioned.

 

Line 163 states: "The rough surface increases the surface area, which helps to improve functionalities such as antimicrobial activity, UV protection, oxidation resistance and enhanced wash resistance."

All other mechanisms are discussed later in the passage, but wash resistance. Actually

It would be beneficial to the specific chemical or physical bonding mechanisms (e.g., covalent bonds, ionic interactions, hydrogen bonds, van der Waals forces) between the chitosan/sericin and the cotton fibre that make this adhesion strong enough to withstand washing. Please explain the precise mechanism at a molecular level. (see comments for line 231-234)

Doing this would also be beneficial to support lines 186-190, discussing the longevity of the antibacterial properties.

 

Line 170: Please consider making the sentence more assertive by removing the word "can" from the sentence "which can form" and making "which forms".

 

Lines 192-194: Please consider removing the "because further increases beyond" and splitting the sentence to make it easier to read.

"Concentrations exceeding 10% do not significantly improve antibacterial properties [92]."

 

Line 219 mentions that dye aggregation occurs, with a slight decline at 2%. While this can be observed in the source [112], no explanation for dye aggregation is mentioned. In the source [113], a plateau of 2% is observed, and there is no decline.

The mechanism of aggregation is not explained in any of the two sources. It is a complicated matter, and it is suggested that it is either removed or better explained.

In his work, the respected Prof. Burkishaw explained the effect of electrolytes in the dye bath, which can promote dye aggregation and reduce dye solubility, with a combinatorial promotional effect when the liquor ratio is reduced. If chitosan in the dyebath acts as an electrolyte, it can promote aggregates. Additionally, chitosan saturation on the fibre decreased the available binding sites, which promotes the formation of dye aggregates. Furthermore, concentrating dye molecules near the fibre surface (due to positive charge) may promote localised aggregation at high concentrations of chitosan.

Line 224-225. Please consider splitting into two sentences as it is hard for the reader to follow the context.

 

Line 231-234. Although the statement is mentioned in the literature [112], I would disagree. Please allow the presentation of the argument. Reactive dyes do not rely on ionic bonding. They react covalently with the substrate. The ionic attraction helps only in the first stage of dye adsorption and not dye-fibre bonding.

The authors mention that the cationic groups in chitosan "strengthen the electrostatic interactions between the fibres and dye molecules, thereby reducing dye desorption and preventing colour fading during laundering". This fact can be applied to direct dyes or reactive dyes. An increase in chitosan concentrations would benefit dye retention due to continuously increasing ionic charge, which does not happen. Therefore, any improvement can only be claimed by the retention of the hydrolysed reactive dye, which possesses a negative solubilising group and, hence, is attracted by the amino groups of the chitosan. Finally, an indirect improvement can also be due to the RSA effect (as mentioned in line 242 and 306).

Therefore, I suggest rewriting the lines 231-234 more clearly.

 

Line 260-261. Please consider substituting for clarity the following:

"Chitosan contains N-acetylglucosamine and glucosamine groups, which contribute to UV absorption, while the phenolic groups in curcumin also exhibit strong UV absorption properties[50,122]."

with the following:

"Chitosan contains N-acetylglucosamine and glucosamine groups that contribute to UV absorption, while the phenolic groups in curcumin also exhibit strong UV-absorbing properties [50,122]."

 

Lines 272-273. Consider splitting the sentence for better understanding.

The

", while the temperature reduction effect was even more pronounced (11.2°C) compared to nylon textiles[51]."

can be written as:

The temperature reduction effect was even more pronounced (11.2°C) compared to nylon textiles [51]."

 

Line 283. The Caption of Figure 8 is excessively long. Consider introducing part to the main text.

Line 302. Change the catalyst NaH₂ to catalyst NaH₂PO₂,

Line 304. The standard textile testing conditions is not "25±2°C" but "20±2°C" (although it is wrongly mentioned in [107]). Please consider correcting it.

Line 309-310. Remove gaps.

Also consider mentioning how the RSA units are measured.

The following text is suggested.

The %RSA activity is measured using the %reduction of the DPPH indicator (2,2-diphenyl-1-picrylhydrazyl), which acts as a stable free radical with a deep violet colour. When it encounters an antioxidant, it accepts an electron or hydrogen atom and becomes reduced, which causes a colour change from violet to yellow. The tested sample is treated with the DPPH and measured with a UV-Vis spectrophotometer at the absorbance at λ=517nm.

A₀ = absorbance of DPPH solution without sample (control)

Aₛ = absorbance of DPPH solution with sample

Line 311. Please remove the 311 (line number moved into table)

Line 319. Consider changing the title of 4.3 to avoid repeating the context of antimicrobial activity (lines 112-198):

4.3 Water-Repellent and Antibacterial Finishing

To

4.3 Water-Repellent and Multi-Functional Activity

 

Line 347. The authors mention improvements in the fabric's mechanical strength and durability. Please explain the mechanism of enhancement. However, the source [109] refers to anti-wrinkle properties, not tensile or durability. It provides the following explanation, which can be included in the text concerning the anti-wrinkle properties.

Once cured, the chitosan creates an insoluble protective layer on the fibre's surface. This layer fortifies the fabric, making it more resistant to deformation. Moreover, chitosan molecules fill the tiny fibre pores, establishing hydrogen bonds between the chitosan and the fibres. These bonds strengthen the amorphous areas, decreasing their movement and preventing wrinkles.

 

Line 366-369. Please consider the following change, as the text confuses the reader over the biochemical methods.

The:

“Currently, wastewater treatment technologies primarily include physicochemical  methods (e.g., adsorption, coagulation-flocculation, and membrane separation) and biochemical methods (e.g., phytoremediation and microbial degradation), which rely on various adsorption mechanisms such as ion exchange, complexation, chelation, electrostatic interactions, and hydrogen bonding[136,137].”

can be better re-written as:

“Currently, wastewater treatment technologies primarily include physicochemical  methods (e.g., adsorption, coagulation-flocculation, and membrane separation), which rely on various adsorption mechanisms such as ion exchange, complexation, chelation, electrostatic interactions, and hydrogen bonding, and biochemical methods (e.g., phytoremediation and microbial degradation) [136,137].”

 

Line 400. Figure 10 (a) third picture and (b) third picture.

SEM analysis detects only surface morphology using electrons, and chromatographic measurements are impossible since no photons are involved. Please explain how this colour is derived. (Strangely enough, source [136] also features these SEM pictures in colour.)
Is it somehow enhanced by the BackScattering Mode (4Q-BSE)

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The summary is a good overview about the use of chitosan. 

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

This manuscript presents an overview of the production of chitosan-based textile materials, application of chitosan in textile dyeing and finishing processes, and textile waste management with chitosan application. The research topic is well framed, stressing the importance of a comprehensive analysis of chitosan applications, particularly “the need for a holistic review of how chitosan can support sustainability at each stage of textile production and disposal” (lines 66-8). The topic is relevant to the field and it falls within the scope of Clean Technologies Journal.

Below I list my comments for the authors appreciation.

My main criticism of this manuscript concerns the lack of presentation of the research methods. Reviews do not necessarily present a research methods section. Nevertheless, they need to clearly state the approach/methodology defined to conducted the review, including data collection and analysis.

In the Abstract, lines 13-4, says: “This review synthesizes findings from 142 academic studies to assess chitosan’s applications in textile production, dyeing, finishing, and waste management (…)”. Besides not being mentioned (in the Abstract or in the main text) how the studies were selected and analyzed, a significant amount of the references is used in the Introduction section and not to analyze the application of chitosan in the textile production.

- Figure 1. If the authors consider relevant to present this ½ page figure, more information should be given besides “Some fibers, such as samples I and J, exhibit smooth surfaces, while others, such as samples K, M, D, and E, display grooved structures (see Fig. 1).” (lines 102-4).

- Section 6. Discussion, line 427 “This review analyses the applications of chitosan in the textile industry”. As presented, the review focuses on academic research, not industry.

In the Keywords, “Renewable Biomaterials for Fashion” is presented. If this is an important topic for the manuscript, shouldn’t current and/or potential application of chitosan in Fashion be discussed?

Additional comments:

- All Figures should be presented/cited in the text before they appear in the manuscript.

- I am not a native English speaker but I consider that the article does not require an English review. I have just noticed line 214: “dying” instead of dyeing.

Author Response

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Author Response File: Author Response.docx

Reviewer 4 Report

Comments and Suggestions for Authors

The manuscript provides a thorough and well-structured overview of chitosan-based composites applied to sustainable textile production, approached from a lifecycle perspective. The subject is both relevant and timely, given the growing environmental challenges faced by the fashion and textile industries. By bringing together information related to fiber production, dyeing, finishing, and wastewater management, the authors offer a meaningful contribution to the academic discourse and to the broader understanding of chitosan’s role in advancing sustainability within the textile sector.

The structure is clear, and the visual elements (figures and tables) effectively illustrate the scientific content. The discussion is particularly strong, providing a thoughtful and critical assessment of the advantages and limitations of chitosan in different stages of textile manufacturing. The potential of chitosan to support decarbonization, promote circularity, and reduce environmental impacts is convincingly presented.

The manuscript cites 142 academic sources, many of which are recent and relevant. Although the number of sources is substantial, the article does not explain how these studies were identified or chosen. Including even a brief explanation of the review methodology would improve the transparency and reproducibility of the work. Furthermore, while the discussion is insightful, the manuscript would benefit from a separate conclusion section that summarizes the main findings, limitations, and future research directions. Lastly, indicating whether the technologies discussed are at the experimental, pilot, or industrial scale would help readers better assess their readiness for application.

Author Response

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Author Response File: Author Response.docx

Reviewer 5 Report

Comments and Suggestions for Authors

The review article entitled "Chitosan-Based Composites for Sustainable Textile Production:
Applications Across the Lifecycle" is a relevant contribution to 
the field of chitosan applications. The fact that the authors limit the discussion to the field of
textile production is necessary; otherwise the article would not have a clear focus and the 
discussion would not be coherent.

The academic writing and the data analysis are clear. 
The article has value for textile researchers not famliliar with chitosan, so the can quickly
gather relevant knowledge. The references are recent and relevant.

There are a few issues:

1) As a minor point, I suggest the authors remove the following 2 phrases: (lines 65-68) "A comprehensive assessment of its role from raw material sourcing to 
end-of-life waste management remains limited[61,62]. This gap highlights the need for a 
holistic review of how chitosan can support sustainability at each stage of textile production and disposal."

Written in that way, the text suggests the authors would address the full chitosan lifecycle from raw material production to disposal issues, which is not the case.

2) Section 2.1 Preparation Process of Chitosan-Based Textile Materials
Unfortunately, the authors give not any information regarding the preparation process; they just list the result how different the fibers finally could 
look like, with no strategy how to influence the fiber morphology. 

3) line 301, the text mentions a finishing solution containing chitosan, sericin, citric acid, and NaH2. What is meant with NaH2? This compound does not exist.

4) Line 374, what is element Ur?
In general, half of this paragraph,  lines 372 to 376 seems to be not relevant since it deals with the removal of  heavy metals from wastewater. 

For all these reasons the article can be accepted with these minor improvements.

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have thoroughly revised the manuscript and the work was improved.

I consider that the paper deserves publication in Clean Technologies Journal.

Author Response

Thank you for the kind words of the reviewer and their recommendation for publication.

As per the request from the editor, we have updated the figures and uploaded them as separate files to improve the file qualities.