A Comparative Approach Study on the Thermal and Calorimetric Analysis of Fire-Extinguishing Powders

Comments from reviewer #1

Response to reviewer 1

1.      The selected keywords are so extensive, not indicating the topic and innovation of this manuscript. For example, FTIR, XRD, etc.

Your feedback regarding the keyword selection is greatly appreciated. After careful consideration, we concur that the initial selection was excessively general and failed to adequately emphasize the fundamental subjects and fresh elements of our research. A revision has been made to our keywords in order to better align with the precise scope and innovative contributions of our research. Structural Analysis, Expansible Graphite (EG), Potassium Bicarbonate (KHCO₃), Thermal Properties, Suppression Efficiency, and Gaseous Emissions are the newly added keywords. These terms, in our opinion, more accurately capture the essence of our work and its significance within the field.

2.      The Introduction is too concise, and there is no investigation or summary of the studies on the relationship between calorimetric properties and thermodynamic properties of materials, and it is difficult to highlight the research purpose.

Your insightful comments concerning the Introduction of our manuscript are greatly appreciated. We concur that a summary of studies examining the correlation between calorimetric and thermodynamic properties of materials, particularly as they pertain to fire suppression, would enhance the informativeness of the Introduction. In response, we have augmented the Introduction to furnish an all-encompassing synopsis of recent investigations in this field, emphasizing its pertinence to our examination of the utilization of potassium bicarbonate and expansible graphite in suppressing metal fires. In addition to providing a more comprehensive understanding of the scientific context, this addition will situate our research precisely in relation to the current body of literature.

3.      The research plan of this paper should be placed after the research purpose.

We appreciate your astute recommendation concerning the structure of our manuscript. We recognize the significance of a coherent structure when delivering our research findings. We will reorganize the manuscript per your suggestion so that the research plan follows the research objective. Making this modification will result in a study presentation that is more cohesive and impactful, in accordance with established protocols for scientific communication. We are grateful for your assistance in improving the coherence and influence of our endeavors.

4.      Some references are so old, and new related references are not cited. For example, Ceramics International, 2023, 49: 7871–7887; Journal of Cleaner Production, 2022, 367: 133107, etc.

Thank you for your valuable feedback regarding the references in our manuscript. We acknowledge the importance of incorporating recent and relevant literature to strengthen our research. In response to your comment, we will thoroughly review and update our references to include more contemporary studies. Specifically, we will integrate recent publications such as those from 'Ceramics International, 2023, 49: 7871–7887' and 'Journal of Cleaner Production, 2022, 367: 133107', which are pertinent to our study's domain. This update will ensure our research is grounded in the latest advancements and trends in the field, enhancing the overall quality and relevance of our work.

5.      In lines 118-120, ‘Different concentrations of the EG-KHCO₃ compositions were delivered to the fire source upon ignition.’, Why do you use the word ‘concentration’ instead of ‘ratio’?

In response to your query regarding the use of 'concentration' instead of 'ratio' in lines 118-120, we used 'concentration' to emphasize the proportion of each component in a homogenous mixture, where each component's presence is measured relative to the entire mixture's volume or mass. This term was selected to specifically denote the quantity of EG and KHCO₃ in relation to the total volume or mass of the extinguishing agent, which is crucial for understanding the efficacy of different compositions in fire suppression. We believe this terminology accurately reflects the experimental conditions and the precision required in our study. However, we appreciate your observation and will clarifying this terminology in the manuscript to ensure the intended meaning is clear to all readers.

6.      In line 132, why do you analyze gaseous by-products at these three temperatures? Specific explanations should be given.

We appreciate your inquiry regarding the analysis of gaseous by-products at three specific temperatures in line 132. The temperatures selected for analysis, namely 135, 210, and 580 °C, were determined based on the critical phases observed during the thermogravimetric analysis. The temperatures mentioned correspond to important milestones in the thermal degradation process of the EG-KHCO3 mixtures, where specific alterations in gaseous emissions were postulated. Examining the gaseous by-products at these temperatures enables a comprehensive comprehension of the chemical reactions taking place at each phase, yielding valuable knowledge regarding the efficacy of fire suppression and the ecological consequences of the emissions. The precise selection of temperature is essential for a comprehensive evaluation of the effectiveness and safety of the fire suppression compositions being studied. The corresponding explanation was added in the manuscript.

7.      Firstly, when stating TG tests, it should be pointed out that nitrogen atmosphere was adopted in TG tests. Secondly, why do you choose nitrogen atmosphere in TG tests?

We appreciate your feedback on the TG tests. Your observation regarding the absence of the specific atmospheric conditions used in these tests is accurate, and we value your meticulousness. The revised manuscript will clearly indicate that a nitrogen atmosphere was utilized during the TG tests. The decision to use a nitrogen atmosphere was intentional, as it creates a non-reactive environment that inhibits oxidation and combustion reactions. The lack of reactivity is essential for conducting precise investigations on the thermal decomposition and stability of the EG-KHCO3 mixtures, free from any external reaction interference. In this environment, our observations and conclusions are solely derived from the intrinsic characteristics of the materials being studied.

8.      In line 192, what is the ‘thermal resilience’?

We appreciate your inquiry concerning the definition of "thermal resilience," which appears in line 192. The term 'thermal resilience' as used in our manuscript pertains to the capacity of the EG-KHCO3 compositions to retain their structural integrity and functional efficacy when exposed to elevated temperatures, which are commonly encountered in fire situations. More precisely, it signifies the material's ability to endure elevated temperatures without undergoing significant chemical changes or thermal degradation, while still effectively suppressing fires. The assessment of the appropriateness of these compositions for fire suppression purposes, specifically in demanding settings like metal fires, hinges on this fundamental principle. For the sake of clarity, we added this definition is explicitly stated in the revised manuscript.

9.      In 197 lines, an extra ‘)’ is found in the text.

W appreciate your attention to the typographical error that appears on line 197. In order to ensure the text's clarity and grammatical accuracy, the additional ')' will be rectified. Your meticulousness is greatly appreciated, and we are fully dedicated to upholding a superior level of precision and clarity in our manuscript.

10.  The TG tests results are not explained and analyzed in detail in Section 3.1.

Your constructive feedback regarding Section 3.1 concerning the TG test results is greatly appreciated. It is acknowledged that comprehensive elucidation and examination of these outcomes are necessary to validate our conclusions. We added the following sentences in the end of section 3.1. “The thermogravimetric analysis presented in the figures commences by examining the compositions of EG-KHCO₃. These compositions exhibit a consistent weight until reaching a certain temperature threshold, indicating an initial state of thermal stability. With an increase in temperature, there is a noticeable decrease in weight, which is indicated by a peak in the differential thermal gravity curve. This peak represents an important stage of decomposition for the expansible graphite. The decomposition phase is noticeably altered when potassium bicarbonate is present, indicating an interaction that improves the composite material's ability to withstand high temperatures. The residual weight percentage observed at high temperatures indicates the presence of a stable residue, which is likely responsible for the material's effectiveness in suppressing fires. When analyzing the thermal properties of the mixtures in comparison to pure EG, the inclusion of KHCO₃ seems to create a synergistic impact that alters the thermal degradation pattern, suggesting enhanced fire retardant abilities. This observation is significant because it corresponds with the desired result of increased effectiveness in suppressing metal fires, which is particularly important in situations where the ability of the suppression agent to withstand high temperatures is of utmost importance. The comprehensive analysis of TG/DTG concludes by identifying the 3:1 EG-KHCO₃ ratio as a highly promising composition. This composition offers improved thermal stability and has the potential to enhance fire suppression performance.”

11.  In lines 204-205, the sentence of ‘EG-KHCO₃ mixes had a notable impact on the amount of agent utilized’ needs to be explained.

Your inquiry for additional clarification concerning lines 204-205 is greatly appreciated. The phrase "significant influence on the quantity of agent employed" pertains to the quantitative consequences that various EG-KHCO₃ mixture proportions impose on the volume or mass of the fire suppression agent that is necessary to put out a fire. Our revisions included a more comprehensive elucidation of the methods by which these particular mix ratios were optimized to improve the efficiency of suppression. As a consequence, an overall reduction in agent usage was achieved, thereby ensuring effective fire suppression. The course will encompass an analysis of the methodology employed to ascertain the most effective mix ratios, as well as the consequential ramifications for real-world implementations in fire prevention. We added the sentences “The experimental findings showed that specific ratios, specifically the 3:1 EG-KHCO₃ mixture, enabled a decrease in the amount of substance required to effectively control fires, while maintaining suppression effectiveness. The discovery is noteworthy, indicating that the improved combination proportions enhance the fire-suppression capabilities of the substance, potentially resulting in financial savings and decreased environmental harm.” in the section 3.2.

12.  In lines 216-230, are these descriptions corresponding to Figure 5?

The description presented in Figure 5 corresponds precisely to the data and observations contained in lines 216-230. In order to provide further clarity, the chemical pathways and interactions that were discerned during our analyses and are elaborated upon in this particular section of the manuscript are depicted in Figure 5. Thorough efforts have been made to ensure that the text faithfully represents the visual data depicted in the figure, thereby furnishing a unified and all-encompassing elucidation of the findings.

13.  Section 3.4 only analyzes the reaction path of KHCO₃ but does not consider the interaction between KHCO₃ and EG.

"We appreciate your insightful comments regarding Section 3.4. The initial investigation was constrained in scope to examine the reaction pathway of KHCO₃, as a result. A comprehensive analysis of the interactions between KHCO₃ and EG was not within its purview. We acknowledge the significance of comprehending the interplay between these components and the possible ramifications for the effectiveness of fire suppression. Although the present study did not encompass this particular interaction, we propose it as a significant avenue for future research to expand upon the results that have been presented thus far.

14.  In lines 368-372, the content here should be placed in Conclusion.

We value your input concerning the substance found in lines 368-372. After careful examination, we concur that the information would be more suitably situated in the Conclusion segment. By transferring the concluding remarks, it will be possible to ensure that they effectively summarize the findings of the study and their implications. The manuscript will be revised in accordance with this change.

15.  Conclusion is not a repetition of all data and results in the paper, and it is necessary to extract the key conclusions and important data.

Thank you for your insightful feedback on the Conclusion section of our manuscript. We acknowledge the importance of summarizing key findings rather than repeating all data and results. In the revised manuscript, we will focus on distilling the core conclusions and significant data points that encapsulate the essence and implications of our research. This revision will enhance the clarity and impact of the Conclusion, ensuring it succinctly conveys the study's contributions to the field of fire suppression.

Comments from reviewer #2

Response to reviewer 2

1.      To enhance the reader's comprehension of the study, the abstract should include more quantitative data. This will facilitate a better understanding of the entire paper.

Your suggestion to augment the abstract with additional quantitative data is greatly appreciated. We concur that incorporating precise numerical findings will augment the reader's understanding of the extent and importance of the study. Important quantitative findings, including the precise temperature ranges within which the material remains stable, the precise reduction in fire extinguishing time, and the rate of cooling facilitated by the EG-KHCO₃ compositions, will be included in the revised abstract. This revision will provide a succinct yet all-encompassing synopsis of the study's pivotal data, facilitating readers' comprehension of the paper as a whole.

2.      Insufficient analysis of the influence of porosity change on fire extinguishing efficiency in the test. It is suggested that additional information be included regarding the relationship between porosity trends and fire suppression. This will provide a deeper comprehension of the effectiveness of fire extinguishing agents to the readership.

We appreciate your recognition of the necessity for a more comprehensive examination of the relationship between changes in porosity and the effectiveness of fire suppression systems. This aspect is recognized as critical for comprehending the efficacy of fire extinguishing agents. We augment the manuscript with supplementary data and an analysis concerning the correlation between alterations in the porosity of the EG-KHCO₃ compositions and their efficacy in suppressing fires in Section 3.5.

3.      It is necessary to provide a more thorough description of the sodium fire extinguished during the experiment. This will facilitate readers in comprehending the experiment's overall content.

We appreciate your recognition of the necessity for an expanded exposition regarding the sodium fire employed in our investigations. In the revised manuscript, specifically in section 3.2, we have furnished an elaborate depiction of the sodium fire

4.      There should be a more comprehensive description and analysis of the repeated firefighting experiments. This will help readers comprehend the experimental procedure, the validity of the results, and the overall effectiveness of the evaluated fire extinguishing agent.

We appreciate your insightful recommendation regarding the necessity for a more thorough exposition and evaluation of the iterative firefighting experiments. Both the validity of our results and the efficacy of the fire extinguishing agent under evaluation are contingent upon this factor, which we duly recognize. We elaborate on the experimental procedure in the revised manuscript in the 2.2. experiment section, with a specific focus on the necessity of conducting the tests multiple times in order to ascertain their reliability. Data will be provided regarding the number of repetitions performed, the consistency of conditions maintained throughout the tests, and the manner in which these repetitions served to validate the efficacy of the EG-KHCO3 compositions. The purpose of this improved description is to assure readers of the experimental methodology and the reliability of our results.

5.      The decision to compute the rate of temperature change between 200 and 350℃ requires further explanation and analysis. Providing computational reasoning and additional pertinent data will strengthen the analysis.

We appreciate your insightful feedback. We recognize the significance of providing a clear explanation and analysis of our decision to calculate the rate of change in temperature between 200 and 350 °C. In our revised manuscript, we will provide a more thorough explanation of our computational reasoning, including why we selected this particular temperature range and how it affects the overall fire suppression efficacy of the evaluated fire extinguishing agent. In addition, we will incorporate additional data to support our analysis. This additional information, we believe, will provide readers with a more thorough understanding of our methodology and strengthen our analysis. We appreciate your suggestion and will include this crucial detail in the revised version of our manuscript in 3.1.section.

6.      The thermogravimetric analysis results depicted in Figures necessitate a more comprehensive analysis. Figure would benefit from additional explanation and analysis.

We appreciate the perceptive remarks that you posed. The results of a thermogravimetric analysis are illustrated in Figure 2. Your recommendation for a more comprehensive analysis of these results is greatly appreciated. We intend to supplement the manuscript with further elucidation and evaluation of Figure 2, along with an exhaustive discourse on the discernible patterns and their implications. Furthermore, we shall highlight noteworthy characteristics or trends in the outcomes and deliberate on their ramifications for the overarching conclusions of the research. It is our conviction that this supplementary examination will enhance the reader's understanding of the thermogravimetric analysis findings and contribute to the scientific merit of our research. We value your recommendation and shall incorporate this essential particularity into the revised iteration of our manuscript. This section has been rewritten per the reviewer's recommendation.

7.      It is crucial to standardize the format in order to satisfy the requirements of the Safety. The inventory of references should only contain works that have been published or accepted for publication and that have been cited in the text. Personal communications and unpublished works must be cited exclusively in the text. The entries in the reference list must be numbered consecutively.

We appreciate your alerting us to the importance of establishing a standardized format in order to comply with "Safety" regulations. We acknowledge and value your feedback. We wish to assure you that we will ensure strict adherence to the journal's specific reference format requirements in the revised manuscript. Only works that have been cited in the text and have been published or accepted for publication will be incorporated. Furthermore, we shall ensure that the reference list entries are numbered consecutively, as stipulated by the journal. We have meticulously revised and edited it in accordance with the suggestions provided.

Comments from reviewer #3

Response to reviewer 3

1.      In order to improve the reader's understanding of the study, the abstract should incorporate more quantitative data. This will enhance comprehension of the entire material.

We appreciate your suggestion to add quantitative data to the abstract. We agree that accurate quantitative data will help readers understand the study's scope and significance. Quantitative results like the material's stable temperature ranges, fire extinguishing time reduction, and EG-KHCO₃ composition cooling rate will be in the revised abstract. This revision aims to summarize the study's key data in a concise and comprehensive manner to help readers understand the paper.

2.      It is recommended to provide further details about the correlation between porosity patterns and fire suppression. This will enhance the readership's understanding of the efficacy of fire extinguishing products.

We appreciate your acknowledgement of the need for a more thorough study of porosity and fire suppression system efficacy. This is crucial to understanding fire extinguisher effectiveness. We add data and analyze the relationship between EG-KHCO₃ porosity and fire extinguishing effectiveness in Section 3.5.

3.      A more comprehensive description of the sodium fire extinguished during the experiment must be provided. This will aid readers in understanding the experiment's overall substance.

We acknowledge your understanding of the need for a more extensive explanation regarding the use of sodium fire in our investigations. In the revised manuscript, particularly in section 3.2, we have provided a detailed portrayal of the sodium fire.

4.      A more thorough depiction and examination of the recurring firefighting experiments is necessary. This will aid readers in understanding the experimental technique, assessing the validity of the data, and determining the overall efficacy of the examined fire extinguishing agent.

We appreciate your constructive feedback. We concur that a more thorough description and analysis of the repetitive firefighting experiments would enhance the reader's comprehension of our study. In our revised manuscript, we provided a more thorough description of these experiments, including the conditions under which they were conducted, the number of repetitions, and the consistency of the results. We will also provide a more comprehensive analysis of the results, discussing their implications for the overall efficacy of the evaluated fire extinguishing agent. We believe that this additional information will enhance the reader's comprehension of our experimental procedure and the reliability of our results.

5.      Further elucidation and analysis are necessary to justify the choice of calculating the rate of temperature alteration between 200 and 350 °C. Enhancing the analysis can be achieved by using computational reasoning and relevant supplementary data.

We appreciate your insight. We recognize the importance of a concise explanation and evaluation of our choice to compute temperature variation from 200 to 350 °C. In our revised manuscript, we explained our computational logic, including why we chose this temperature range and how it affected the fire extinguishing agent's effectiveness. Our analysis will be strengthened by adding additional data. We believe this additional information will improve readers' understanding of our methodology and analysis. We will include your important suggestion in our revised manuscript.

Comments from reviewer #4

Response to reviewer 4

1.      The reviewed article is a well-elaborated comparative approach study focused on thermal and calorimetric analysis of the fire-extinguishing powders. The "Abstract" concisely describes content of the article. The "Introduction" chapter provides a sufficient amount of basic information summarised the issue addressed. The experiments carried out are described clearly and understandably. The focus chapter is the third chapter "Results and Discussions", which is elaborated in a wide range, namely within six subchapters. However, the subchapter 3.6 is followed by the Conclusions chapter, which is numbered fifth in order. Probably, this is a formal error that needs to be corrected. In addition, I recommend improving readability of Fig.2. It is evident that the authors are professionally well-oriented in the given research area. I can say that this article meets the criteria of a scientific-research work and I recommend its publication after incorporating of the above-mentioned comments.

We appreciate your comprehensive evaluation and favorable remarks regarding our manuscript. Regarding the 'Results and Discussions' chapter in particular, we appreciate your recognition of the work's comprehensive nature. With respect to the structural error pertaining to the chapter numbering, we shall rectify this without delay in order to guarantee the appropriate sequencing of the 'Conclusions' chapter subsequent to subchapter 3.6. In addition, to improve the readability of the document, we included an additional explanation for Figure 2 in section 3.1. We express our sincere gratitude for your support and endorsement regarding the publication of our article. We will diligently integrate your insightful recommendations in order to further enhance the manuscript.

Comments from reviewer #5

Response to reviewer 5

1.      A too large amount of self-citability (I counted 9 works by the authors themselves), which amounts to almost 30%.

Your attention being drawn to the matter of self-citability is greatly appreciated. Recognizing the significance of maintaining a balanced reference list, we are cognizant of the current high proportion of self-cited works. To promote a more comprehensive portrayal of the present state of research in our discipline, we intend to assess our references and decrease the quantity of self-citations.

2.      The work does not mention how much of the material to be extinguished (immediately or gradually, at what time) is poured onto the source of the fire.

Your observation regarding the insufficient description of the extinguishing material's application is appreciated. In the 2.2 experiments section of the revised manuscript, we have provided precise details regarding the amount of extinguishing material utilized on the fire source, the methodology employed for application, and the timing of said application. Enhancing comprehension of the experimental methodology and its influence on the outcomes will be facilitated.