Round 1

Reviewer 1 Report

The authors did a detailed study on the Ionic liquid with sodium bentonite and microcrystalline cellulose. 

1. The statistics were not performed on any of the analysis to show the significance of difference.

2. The hydrogel porosity is unclear from the SEM images. Please provide any other characterization for porosity and pore size.

Author Response

Dear Reviewer.

We thank you for the valuable comments which were made while reading our article.

We have tried to correct the manuscript by following your comments.

 

1. Issue: The statistics were not performed on any of the analysis to show the significance of difference.

Reply:    We have added measurement errors to the sections on phase transitions and thermal degradation of ionogels (Tables 3-5).

 

2. Issue: The hydrogel porosity is unclear from the SEM images. Please provide any other characterization for porosity and pore size.

Reply:   Usually, we use the method of low-temperature adsorption-desorption of nitrogen vapors to evaluate porosity (For example [Noskov, A.V.; Alekseeva, O.V.; Shibaeva, V.D.; Agafonov, A.V. Synthesis, structure and thermal properties of montmorillonite/ionic liquid ionogels. RSC Adv. 2020, 10, 34885-34894.  DOI: 10.1039/d0ra06443b ] ). And we tried to perform these measurements for the synthesized triple IL/Na-Bent/MCC ionogels. However, the recorded isotherms did not have a monolayer saturation area and hysteresis loops. This does not allow using the BET and BJH models and finding quantitative parameters of material porosity. We think that this is due to the filling of the pores with the ionic liquid.

Reviewer 2 Report

PDF attached

Comments for author File: Comments.pdf

The quality of English in this manuscript is of average grade, with minor editing required. Overall, the authors have conveyed their research findings and ideas effectively. However, there are some areas where the language could be improved for better clarity and coherence. The manuscript would benefit from careful proofreading to address grammatical errors, sentence structure, and word choice. Additionally, some paragraphs could be rephrased to enhance the flow of the text. Despite these minor language issues, the main ideas and scientific content are well presented, and the paper is understandable to a broad audience. With some editing, the manuscript can meet the required language standards for publication.

Author Response

Dear Reviewer.

We thank you for the valuable comments which were made while reading our article.

We have tried to correct the manuscript by following your comments.

 

1. Issue: The introduction discusses the importance of developing multifunctional materials from natural polysaccharides like cellulose. It introduces ionic liquids as alternative solvents for cellulose and discusses the potential of incorporating inorganic fillers. While it highlights the advantages of ionic liquids, it would be helpful to mention the drawbacks, such as toxicity, cost, and environmental impact.

Reply:  We have added several sentences to the text about the disadvantages of ILs:

However, along with the advantages, ILs have significant disadvantages. For example, according to [14 in new version], generally, ILs are 5–20 times more expensive than molecular solvents. In many cases, this is due to expensive multi-stage synthesis. In addition, because their ionic nature, ILs are often corrosive. Therefore, special containers are needed in potential industrial processes. It has been already demonstrated that most ILs exhibit higher toxicity in comparison to common organic solvents such as methanol and dichloromethane [15 in new version]   (Page 2, lines 61-66 in new version)

 

2. Issue: The introduction provides an overview of cellulose ionogels with inorganic fillers but lacks a statement of how the study contributes to the field. Adding a paragraph on the novelty and significance of the findings would strengthen the introduction section.

Reply:   We have added several sentences to the text in the introduction section (Page 3, lines 97-105 in new version)

XRD analysis showed an increase in the interlayer space of Na-bentonite in ionogels due to the intercalation of IL molecules. The prepared triple IL/Na-Bent/MCC ionogels were characterized by a greater thermal stability than those without cellulose. The electrical conductivity of both triple IL/Na-Bent/MCC and binary IL/MCC ionogels was non-monotonous.    

The present paper is a continuation of our studies of triple ionogels with halloysite as a clay filler [26 in new version]. Therefore, the information on the properties of triple ionogels (but with bentonite as a clay filler) obtained in the current study is new and can be used in describing the effect of the clay filler nature in such systems.

 

3. Issue: The description of the structure of montmorillonite (MMT) and its properties as an inorganic filler is well explained. However, it would be helpful to mention why Na-bent was selected as the inorganic filler for this study and how it differs from other types of bentonite or clay minerals. The introduction mentions the investigation of morphology, structure, thermal behavior, and ionic conductivity of the IL/Na-Bent/MCC ionogels. Consider adding a few sentences about the potential implications of understanding these properties for practical applications or future research in the field.

Reply:   In the current study, Na-bentonite was used as an inorganic component, since exchangeable Na cations can be replaced by IL cations (Page 2, lines 83-84 in new version) 

Also, we have added:   Obviously, such studies can contribute to the search for conditions for the targeted synthesis of ionogels with controlled properties and, as a result, with important practical applications  (Page 2, lines 92-94 in new version)

 

4. Issue: Authors should discuss potential sources of error or uncertainty in the synthesis and characterization processes, and how they were addressed or minimized.

Reply:    To reduce uncertainty, all reagents were dried prior to synthesis. The errors of the measurements results corresponded to the errors of the instruments. In addition, we tried to minimize errors in the following ways. Before SEM experiments, the samples were dried to obtain more reliable information. In XRD experiments, the cuvettes were completely filled with the test substance. In DSC measurements, to minimize the role of water, the data obtained in the second heating were used (Page 3, lines 116-117 and Pages 4-5, lines 149-176  in new version).

 

5. Issue: The method mentions ‘IL excess’ as a condition for adding additional clay to the mixture. However, the criteria for determining the IL excess and the specific procedure for incorporating the extra clay need to be clarified to ensure consistency in the preparation.

Reply:   During centrifugation, the ionogel is separated into the main quasi-solid mass and the IL phase. The liquid is taken with a volumetric pipette and then, based on the ratio of the main mass in the ionogel (IL:MCC:clay), the required amount of clay is mixed with the selected IL, introduced into the main ionogel, and all the previous steps (mixing, ultrasonic treatment, and drying) are repeated to obtain the ionogel.

We have made appropriate changes to the text (Page 3, lines 128-132  in new version ).

 

6. Issue: The results and Discussion section presents significant findings on the properties of the IL/Na-Bent/MCC ionogels. The discussion on the XRD patterns of Na-bentonite and its intercalation with IL molecules is informative. However, it would be advantageous to discuss the potential implications of the intercalation of IL molecules on the properties of the ionogels, especially in terms of enhanced thermal stability or electrical conductivity.

Reply: We have added to the text:

It should be noted that the BMImAc molecules intercalated into Na-bentonite are more difficult to thermally decompose than those that do not interact with clay. As can be seen from the comparison of the data in Tables 4 and 5, for the BMImAc/Na-Bent composite, the characteristic temperatures of the second stage are higher than for pure IL ( Page 6, lines 220-223 in new version ).

 

7. Issue: The investigation lacks potential practical applications of the synthesized ionogels. Discussing specific applications or industries where these ionogels could be beneficial, based on their enhanced thermal stability and electrical conductivity, would provide more relevance and interest to potential readers.

Reply: We have added to the Conclusion section:

The synthesized and studied triple ionogels are of great practical interest for electrochemical devices, flexible electronics, as CO₂ absorbers, antibacterial coatings, etc. ( Page 16, lines 450-452  in new version )

 

8. Issue: The conclusion provides a concise summary of the study's findings and highlights the potential applications of the synthesized ionogels. However, the authors should discuss the implications of their findings and identify any areas for future research.

Reply:   We have added to the Conclusion section a phrase about the planned studies of the nonmonotonic dependence of the electrical conductivity on the composition of the ionogel ( Page 16, lines 448-450 in new version ).

 

9-10. Issues: It would be valuable to mention any potential commercial applications of the synthesized ionogels. Are there any specific industries or products where these materials could be used, and if so, what advantages would they offer? Including such information would make the conclusion more informative and relevant to a broader audience.

This manuscript holds the potential to contribute significantly to environmentally friendly multifunctional materials. Addressing the mentioned concerns and making necessary revisions will improve the manuscript's impact.

Reply:   We have added new paragraph on prospects for applications and ecological benefits of the synthesized iongels

In the presented article, we proposed an approach for the production of thickened electrolytes, which is an alternative to many technologies for the production of cellulose-containing nanocomposites. The novelty of this approach is that we use an ionic liquid that dissolves cellulose very well. This makes it possible to synthesize solid ion-conducting composites that can be used as electrolytes in current sources and energy storage devices. At the operation end of such an electrolyte, it is easily processed to obtain the initial components: upon interaction with water, cellulose and clay are released, and the ionic liquid is purified from water by distillation. Thus, there is a closed environmentally friendly technology (Page 16, lines 424-433 in new version).

 

Reviewer 3 Report

In this manuscript, the authors prepared an ionogels with MCC and Na-bentonite (Na-Bent) by using ionic liquid (IL) 1-butyl-3-methylimidazolium acetate as a solvent for microcrystalline cellulose (MCC). XRD analysis showed an increase in the interlayer space of Na-bentonite in ionogels due to the intercalation of IL molecules. For triple IL/Na-Bent/MCC ionogels, the characteristic thermal degradation temperatures were higher than the corresponding values for IL/Na-Bent composites. This indicates that the prepared IL/Na-Bent/MCC ionogels are characterized by a greater thermal stability than those without cellulose. It was found that the electrical conductivity of both triple IL/Na-Bent/MCC and binary IL/MCC ionogels was non-monotonous.

 

This work is interesting and can be published in this journal after further improvement.

 

I recommend the publication of this manuscript in this journal after concerning these minor comments.

1.       The writing/language errors is existing in the paper, such as “Example, M. Soheilmoghaddam et al. [20]” (line 70). It should be “For example”.

2.       I would suggest to make a suitable figure or flow-sheet of the whole synthesis procedure. Also add the figure of synthesized ionogel.

3.       In the last paragraph of introduction, the authors should briefly discuss the results of the work.

4.       Make a comparison of this work (results) with the previously published results.

Minor improvement of English is required.

Author Response

Dear Reviewer.

We thank you for the valuable comments which were made while reading our article.

We have tried to correct the manuscript by following your comments.

 

 

1. Issue: The writing/language errors is existing in the paper, such as “Example, M. Soheilmoghaddam et al. [20]” (line 70). It should be “For example”.

Reply:   We agree. Corrections have been made to the text.

 

2. Issue: I would suggest to make a suitable figure or flow-sheet of the whole synthesis procedure. Also add the figure of synthesized ionogel.

Reply:  We have added a scheme of the synthesis procedure (Fig. 1). Images of the synthesized ionogel, as well as a conductive film for possible application in flexible electronics, are shown in the last fragment.

 

3. Issue: In the last paragraph of introduction, the authors should briefly discuss the results of the work.

Reply: We have added several sentences to the text in the introduction section (Page 3, lines 97-105 in new version).

XRD analysis showed an increase in the interlayer space of Na-bentonite in ionogels due to the intercalation of IL molecules. The prepared triple IL/Na-Bent/MCC ionogels were characterized by a greater thermal stability than those without cellulose. The electrical conductivity of both triple IL/Na-Bent/MCC and binary IL/MCC ionogels was non-monotonous.    

The present paper is a continuation of our studies of triple ionogels with halloysite as a clay filler [26 in new version].Therefore, the information on the properties of triple ionogels (but with bentonite as a clay filler) obtained in the current study is new and can be used in describing the effect of the clay filler nature in such systems.

 

4. Issue: Make a comparison of this work (results) with the previously published results.

Reply:  We have added the following to the Conclusion section:

For BMImAc/Na-Bent ionogels, the glass transition temperature was found to be higher than that of pure BMImAc, and this trend this trend was observed for other similar IL/clay ionogels studied previously (Page 16, lines 443-445 in new version).

In addition, in the initial version of the manuscript, we mentioned the previously obtained data on the thermal degradation of the BMImAc/Halloysite composites and assumed that the shape of clay filler particles affects the thermal stability of the BMImAc/clay composites (Page 11, lines 355-359 in new version).