Improving Biomass-Degradation Properties and Nano-Mechanics of Moso Bamboo via a Simple Nitrogen Heat Treatment
Round 1
Reviewer 1 Report
Manuscript Forests - 2006943
Title: “Improving biomass-degradation properties and nano-mechanics of moso bamboo via a simple Nitrogen heat treatment” Xuqin Xiea, Jingyu Xia, Yueping Daib, Tiancheng Yuana, Yanjun Li, and Xinzhou Wang.
COMMENTS TO THE AUTHORS
Introduction.
Line 90-94. The information concerning the conditions and methods of the investigations should be presented in the section “Materials and Methods”.
Materials and Methods.
Line 101. Please supply the full information about the used tube furnace for the heat treatment of bamboo in the presence of nitrogen (name, company, country of origin). Please also describe the used treatment procedure and sizes of bamboo strips.
Line 106. Please correct the capture of Fig. 1.
Line 109. The design of the equation and its explanation do not meet the requirements of the journal.
Line 112. The names of the used methods (FTIR, XRD) must be written in full and separately for each method.
Line 113. Please supply the information about the used FTIR device (name, company, country of origin), samples preparation.
Lines 117-118. The design of the equation and its explanation do not meet the requirements of the journal.
Line 120. Two research methods should not be joined in one title. Each name of the method should be shown separately.
Line 121. Please supply the full information about the used device for the determination of the colour characteristics.
Line 125. Please indicate in detail the used Wet methods for measuring the content of cellulose, hemicelluloses and lignin in bamboo and the applied devices.
Line 131. What does the nanoindentation test mean? Please describe the nanoindentation test procedure and used devices for preparing the samples and testing mechanical properties.
Lines 133-137. The design of the equation and its explanation do not meet the requirements of the journal.
The authors do not also give any information about the used devices for investigations of the samples with SEM, contact angles measuring and biological testing. For all measurements, the number of replicates is not indicated, which testifies to the absence of a statistical analysis of the results obtained.
Results and discussion
Lines 144, 147. It is impossible to understand what a value temperature “it was increased” and then “further increased”.
Line 149. Please clarify why the exposition of “more surface area of the cellulose” decreases the “interfibrillar hydrogen bonding” between the cellulose fibres. Why the text is not supported by the SEM images (A, B, C)?
Line 163. Do the authors study the effect of thermal modification of bamboo on its properties at 160℃?
Line 170. Please indicate the methods for the determination of cellulose, hemicellulose and lignin in bamboo.
Line 175. The diagram in Fig. 5 should be better presented in the form of Table because the changes in the content of cellulose are not remarkable.
Line 179. Do the authors study the effect of the thermal modification of bamboo on its chemical composition at 160℃?
Line 185. What does “the increment of treatment” mean?
Line 186. What kind of reactions can be proceeded “among lignin, acetic acid, and hemicellulose’s by-products?”
Line 194. The full names of the used methods are needed.
Line 195. Did the authors study “the effect of hydrothermal treatment” on the chemical composition of bamboo?
Line 199. What is about a wavelength, which can testify to “the cleavage of acetyl groups to acetic acid”?
Line 223. The capture of Fig. 7 presents the XRD test and contact angles measuring results for the bamboo samples treated at 150℃, 160℃ and 170℃. According to the section “Materials and methods”, bamboo was treated at 150℃, 190℃ and 210℃ only. Why is this disagreement?
Lines 234, 235. What does “introduction of …. temperature” mean? “The contact angle of the treated” what? Please explain how “a free hydroxyl group (-OH)” can decompose.
Line 240. Please explain why the lignin and cellulose content increases on the bamboo surface, leading to higher contact angle value of bamboo. Cellulose is known to be characterised by the high content of hidrophilic hydroxyl groups.
Line 248. What about the device (name, company, country) for investigation using CIE 1976 L*, a*, and b* standard system. How the samples for this study were prepared?
Line 252. Please clarify for readers what ∆E mean.
Line 264. The design of this part of the article does not meet the requirements of the journal.
Line 265. Why do the authors use the term “bamboo cell walls” instead of “bamboo samples” to discuss their mechanical properties?
Line 275. What is about “previous literature”, please give a reference.
Line 276. Please name the factors, which contribute to an increase in bamboo micro-mechanical properties. It should be noted that an increase in the hardness and the elastic modulus cannot indicate an improvement in the mechanical properties, but only an increase in the rigidity of the bamboo samples.
Line 289. Were the bamboo samples further hydrothermally modified?
Line 305. Please indicate the difference between the given schematic diagrams of the thermal modification in Fig. 1 and Fig. 12.
Conclusions
Line 307. Were the research results obtained as a result of the bamboo thermal modification in the presence of nitrogen or the treatment with superheated steam?
Lines 308-317. The conclusions should coincide with the main findings of the article, and that is why they should be major revised.
Author Response
Reviewer 1:
Point 1: Line 90-94. The information concerning the conditions and methods of the investigations should be presented in the section “Materials and Methods”.
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. The information concerning the conditions and methods of the investigations also presented in the section “Materials and Methods”.
Point 2: Line 101. Please supply the full information about the used tube furnace for the heat treatment of bamboo in the presence of nitrogen (name, company, country of origin). Please also describe the used treatment procedure and sizes of bamboo strips.
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. The full information about the tube furnace for the heat treatment of the bamboo in the presence of nitrogen is GSL-1700X-80-HNG, Jingmi Technology., Ltd., Shanghai.
Point 3: Line 106. Please correct the capture of Fig. 1.
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. I don not understand w
Point 4: Line 109. The design of the equation and its explanation do not meet the requirements of the journal.
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. We have revised the equation in our revised version.
Point 5: Line 112. The names of the used methods (FTIR, XRD) must be written in full and separately for each method.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. The methods (FTIR, XRD) is written in full and separately for each method. Thank reviewer for giving us positive and careful suggestions.
Point 6: Line 113. Please supply the information about the used FTIR device (name, company, country of origin), samples preparation.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. The information of used FTIR device has been added in the revised version. Thank reviewer for giving us positive and careful suggestions.
Point 7: Lines 117-118. The design of the equation and its explanation do not meet the requirements of the journal.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. The design of the equation and its explanation have been revised in our revised version. Thank reviewer for giving us positive and careful suggestions.
Point 8: Line 120. Two research methods should not be joined in one title. Each name of the method should be shown separately.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. The name of the method has been shown separately. Thank reviewer for giving us positive and careful suggestions.
Point 9: Line 121. Please supply the full information about the used device for the determination of the colour characteristics.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. The color characteristics have been deleted in our revised version. Thank reviewer for giving us positive and careful suggestions.
Point 10: Line 125. Please indicate in detail the used Wet methods for measuring the content of cellulose, hemicelluloses and lignin in bamboo and the applied devices.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. We have added the detailed wet chemistry method in our revised version. Thank reviewer for giving us positive and careful suggestions.
Point 11: Line 131. What does the nanoindentation test mean? Please describe the nanoindentation test procedure and used devices for preparing the samples and testing mechanical properties.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. We are very grateful to Reviewer for reviewing the paper so carefully. Nanoindentation (NI) is an useful technology that can analyze the nano-mechanics of bamboo from cell wall level. For analyze the effects of heat treatment on the nano-mechanics of bamboo samples, NI was used to this objective. The detailed Nanoindentation equipment and corresponded bamboo samples are shown as below:
Figure 1: Nanomechanics (left) and sample (right).
Point 12: Lines 133-137. The design of the equation and its explanation do not meet the requirements of the journal.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. We are very grateful to Reviewer for reviewing the paper so carefully. We have revised that in our revised version.
Point 13: The authors do not also give any information about the used devices for investigations of the samples with SEM, contact angles measuring and biological testing. For all measurements, the number of replicates is not indicated, which testifies to the absence of a statistical analysis of the results obtained.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. The detailed the information about the used devices for investigation of the samples with SEM, contact angles measuring and biological testing are added in the revised version. The statistical anslysis has been also added in the revised version. Each experiment was repeated 3 times to obtain the average value.
Point 14: Lines 144, 147. It is impossible to understand what a value temperature “it was increased” and then “further increased”.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. The value temperature has been added in the revised version. Thank you for giving us positively suggestion. We are very grateful to Reviewer for reviewing the paper so carefully. We have revised that in our revised version.
Point 15: Line 149. Please clarify why the exposition of “more surface area of the cellulose” decreases the “interfibrillar hydrogen bonding” between the cellulose fibres. Why the text is not supported by the SEM images (A, B, C)?
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. Hemicellulose acts as a matrix in the cell structure and fills in between the cellulose. When exposed to the high temperature, the hemicellulose content decreased, leading to the more surface area of the cellulose exposed. SEM images showed that with the increment of treatment temperature , the three-dimensional structure network structure still remains, but the thin-wall cells distorted and deformed because of the thermo-decomposition reaction.
Point 16: Line 163. Do the authors study the effect of thermal modification of bamboo on its properties at 160℃?
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. We have corrected that in our revised version. We are very grateful to Reviewer for reviewing the paper so carefully. We have revised that in our revised version.
Point 17: Line 170. Please indicate the methods for the determination of cellulose, hemicellulose and lignin in bamboo.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. We have added the method for the determination of cellulose, hemicellulose and lignin in bamboo. The method reported by NERL’S LAPs was applied for the determination of cellulose, hemicellulose, and lignin in bamboo.
Point 18: Line 175. The diagram in Fig. 5 should be better presented in the form of Table because the changes in the content of cellulose are not remarkable.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. We have revised Fig.5 into table1 in our revised version. We are very grateful to Reviewer for reviewing the paper so carefully.
Point 19: Line 179. Do the authors study the effect of the thermal modification of bamboo on its chemical composition at 160℃?
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. We have revised that in our revised version. We are very grateful to Reviewer for reviewing the paper so carefully.
Point 20: Line 185. What does “the increment of treatment” mean?
Response: We are very grateful to Reviewer for reviewing the paper so carefully. It shoule be “the increment of treatment temperature”. we have corrected that in our revised version.
Point 21: Line 186. What kind of reactions can be proceeded “among lignin, acetic acid, and hemicellulose’s by-products?”
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. It should be lignin condensation reaction. We have deleted that in our revised version. We are very grateful to Reviewer for reviewing the paper so carefully.
Point 22 :Line 194. The full names of the used methods are needed.
Response: We are very grateful to Reviewer for reviewing the paper so carefully. The full names of the used methods are applied in our revised version. It is really a detail which should not be neglected as Reviewer suggested and a reference.
Point 23: Line 195. Did the authors study “the effect of hydrothermal treatment” on the chemical composition of bamboo?
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. We have corrected that in our revised version.
Point 24:Line 199. What is about a wavelength, which can testify to “the cleavage of acetyl groups to acetic acid”?
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. The wavelength of 1730 cm -1 can testify the cleavage of acetyl groups to acetic acid. We have revised the FTIR analysis in our revised version.
Point 25:Line 223. The capture of Fig. 7 presents the XRD test and contact angles measuring results for the bamboo samples treated at 150℃, 160℃ and 170℃. According to the section “Materials and methods”, bamboo was treated at 150℃, 190℃ and 210℃ only. Why is this disagreement?
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. We have corrected this mistake in our revised version. We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions.
Point 26:Lines 234, 235. What does “introduction of …. temperature” mean? “The contact angle of the treated” what? Please explain how “a free hydroxyl group (-OH)” can decompose.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. “introduction of …. temperature” has been revised into “after nitrogen thermal modification”. It should be “The contact angle of the treated bamboo samples”. In addition, we have added the explaination of how “a free hydroxyl group (-OH)” decompose in our revised version.
Point 27:Line 240. Please explain why the lignin and cellulose content increases on the bamboo surface, leading to higher contact angle value of bamboo. Cellulose is known to be characterised by the high content of hidrophilic hydroxyl groups.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. It has been revised into ‘the lignin content increases on the bamboo surface, leading to higher contact angle value of bamboo”.
Point 28:Line 248. What about the device (name, company, country) for investigation using CIE 1976 L*, a*, and b* standard system. How the samples for this study were prepared?
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. We have deleted this section in our revised version. We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions.
Point 29:Line 252. Please clarify for readers what ∆E mean.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. We have deleted this section in our revised version. We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions.
Point 30: Line 264. The design of this part of the article does not meet the requirements of the journal.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. We have revised that in our reivsed version. We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions.
Point 31:Line 265. Why do the authors use the term “bamboo cell walls” instead of “bamboo samples” to discuss their mechanical properties?
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. We used “bamboo samples” instead of “bamboo cell wall” in our revised version. We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions.
Point 32:Line 275. What is about “previous literature”, please give a reference.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. we have added the reference in our revised version. We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions.
Point 33:Line 276. Please name the factors, which contribute to an increase in bamboo micro-mechanical properties. It should be noted that an increase in the hardness and the elastic modulus cannot indicate an improvement in the mechanical properties, but only an increase in the rigidity of the bamboo samples.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. The hardness and modulus of elasticity of bamboo cell walls affected by many factors, such as moisture content, cellulose microfibril angle, cellulose crystallinity degree, hemicellulose, and lignin. In this manuscript, we think the increased lignin content can contribute to an increase in bamboo micro-mechanical properties.
Point 34:Line 289. Were the bamboo samples further hydrothermally modified?
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. We have corrected that in our revised version. We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions.
Point 35:Line 305. Please indicate the difference between the given schematic diagrams of the thermal modification in Fig. 1 and Fig. 12.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. Figure 1 shows the processing of the bamboo samples. Figure 12 shows the increased water contact angle of treated bamboo samples. In addition, the increased lignin, decreased hemicellulose and cellulose also presented in Figure 12. We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions.
Point 36:Line 307. Were the research results obtained as a result of the bamboo thermal modification in the presence of nitrogen or the treatment with superheated steam?
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. The research results obtained as a result of the bamboo thermal modification in the presence of nitrogen. We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions.
Point 37:Lines 308-317. The conclusions should coincide with the main findings of the article, and that is why they should be major revised.
Response: It is really a detail which should not be neglected as Reviewer suggested and a reference. The conclusion has been revised. We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions.
Author Response File: 
Author Response.docx
Reviewer 2 Report
This is a very well written manuscript. All sections are complete, in my opinion, and there is no need to make many corrections.
Line 143 -- reference to Figure 4 is not needed
Section 3.3 -- There is no indication what the control or non-TM bamboo would have for hemicellulose, cellulose and lignin for comparison to the TM. This should be noted in this section. Also, the graphs do not have error bars on the column chart. Can this be added to support the discussion statistically?
Figure 7(H) What is this? Out of place?
Section 7 - Italic font ... change back to normal font
Author Response
Reviewer 2:
Point 1: Line 143 -- reference to Figure 4 is not needed
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. We have deleted the reference to Figure 4 in our revised version.
Point 2: Section 3.3 -- There is no indication what the control or non-TM bamboo would have for hemicellulose, cellulose and lignin for comparison to the TM. This should be noted in this section. Also, the graphs do not have error bars on the column chart. Can this be added to support the discussion statistically?
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. We have added the hemicellulose, cellulose, and lignin of the control in our revised version. We added the statistical analysis in our revised version and added the error bars on the column to support the discussion statistically.
Point 3: Figure 7(H) What is this? Out of place?
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. We have deleted the Figure 7H in our reivsed version.
Point 4: Section 7 - Italic font ... change back to normal font
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. We have change back to normal font in our revised version.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Comments for author File: Comments.doc
Author Response
Point 1: Line 101. The sizes of bamboo samples are not indicated.
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. Firstly, the moso bamboo was split and cut into bamboo strips with the average size of 100 mm × 20 mm × 6 mm (length × width × thickness). The initial density and moisture content of moso bamboo were 0.75 g/cm3 and 85 %.
Point 2: Line 106. According to Fig. 1, the amount of the holes on the surface of the sample before and after the treatment is the same; the samples are differed by color only. What is the difference between the initial sample and modified one in accordance with this scheme.
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. The holes on the surface of the sample represents the vascular bundles. The amount of vascular bundles will not change after thermal modification. It is only a schematic of the thermal modification process of the thermal modification. The change in color is due to the change of main chemical composition during the thermal modification. After thermal modification, the hemicellulose and cellulose content decreased, while the lignin content increased. Thus, modified bamboo become darker the the anti-mildew property, dimensional stability, micro-mechanical property and so on will change at the same time.
Point 3: Line 109. The design of the equation (1) is not fully meet the requirements of the journal.
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. The design of the equation (1) has been revised in our revised version.
Point 4: Line 112. The names of XRD must be written in full.
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. The names of XRD has been written in full in our revised version.
Point 5: Line 127 (in the REVISED VERSION). Please once more indicate what methods of wood chemistry according to TAPPI or ASTM or Chinese National Methods were used for the determination of the content of cellulose, lignin and hemicelluloses in bamboo? The NREL’S LAPS system involves the spectra of different analytical and instrumental methods, each of them has its own name and can be used with an appropriated device.
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. The detailed experimental process has been added in revised version. Weigh 300 mg of the sample, place it at the bottom of the glass tube, add 3 ml of 72 % H2SO4, and stir thoroughly with a glass rod. The test tubes were placed in a water bath for 60 minutes. Add 84 ml of deionized water and dilute the concentrated sulfu-ric acid to 4%. Then, the solution was washed to neutral with water through a vacuum pump. The hydrolysate and the sample residue after reaction were used to measure the hemicel-lulose and lignin content respectively. The cellulose content was obtained from the known hemicellulose and lignin content. The main chemical compositions (cellulose, hemicellulose, and lignin). The methods of wood or bamboo chemistry according to NREL’S LAPS. Liquid chromatography (Agilent 7890A Series, Thermo Fisher) was applied for determining the content of hemicellulose and lignin. The content of cellu-lose was obtained from the known hemicellulose and lignin content.
Point 6: Line 131. Please insert the explanation of the nanoindentation test procedure and used device for preparing the samples from authors’ s answers in the paper text as well as indicate the reference “reported by Previous literature”.
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. The explanation of the nanoindentation test procedure and used device for preparing the samples from authors’ answers in the paper test has been added in to the revised version. The reference has been added in the revised verion too.
Point 7: Line 127 (in the REVISED VERSION). What is the SPSS analysis?
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. Spss software was applied for determinating the significant difference between the groups. The characteristic values of normality and homogeneity of variances were applied for analyzing the results of the measured data. Duncan multiple range tests were conducted to determine the significance between samples. The randomized block design was used in this experiment to minimize the effect of raw material variation on the test results.
Point 8: Line 149. The authors did not explain why “more surface area of the cellulose” decreases the “interfibrillar hydrogen bonding” between the cellulose fibres.
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. Because hemicellulose acts as a substrate filled with cellulose, as the hemicellulose degrades, less hemicellulose is attached to the cellulose skeleton, so more area is generated on the cellulose surface. The connection between cellulose is mainly based on the intermolecular force. With the reduction of hemicellulose, the matrix filling between cellulose is less, which leads to the reduction of hydrogen bonding.
Point 9:Line 204 (in the REVISED VERSION). The design of the Table is not fully meet the requirements of the journal.
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. The table has been revised in our revised version.
Point 10: Line 222 (in the REVISED VERSION). Please explain how the condensation reaction of lignin can contribute to its increased content in bamboo?
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. Among the structural units of lignin, the carbon atom of the side chain of one lignin molecule is C-linked with the carbon atom of the benzene ring of another structural unit, thus forming the lignin condensation with large molecular weight. As a result, the lignin is difficult to degrade and the lignin content increases
Point 11: Line 235. I would like to receive explanation how “a free hydroxyl group (-OH)” can decompose? The authors can decompose only a composition that consists of two or more components, but functional groups can be converted or transformed due to appropriates reactions.
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. The -OH mainly existed in hemicellulose. During the heat treatment process, the force between hydroxyl groups and hemicellulose weaken, thus the hydroxyl group decreased.
Point 12:Line 276. I do not understand why the authors explain an increase in the values of the hardness and the elastic modulus of the samples by only the condensation of lignin. According to the obtained results (line 195 in the revised version), the content of cellulose decreases with the temperature, but a cellulose content is a main factor for increasing the mechanical properties of lignocellulosic samples. It is important to know about the values of tensile and bending properties of the obtained bamboo samples. I am sure they will be unsatisfactory.
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. The nanomechanical properties of the cell walls are generally influenced by crystallinity, moisture content (MC), chemical composition, density, and MFA. The changes of relative crystallinity significantly influence the E and hardness. The amorphous regions of cellulose affect the mechanics of the fiber in the cross-sectional direction, while the proportion of the crystalline regions are the main determinant of the longitudinal nanomechanical properties of the cell walls. Lignin provides stiffness support for bamboo cell walls. Macro-mechanical properties such as bending properties and values of tensile can be decreased due to the thermal modification. However, our manuscript in this word focus on the micro-mechanical properties and anti-mildew property.
Point 13: Line 313 (in the REVISED VERSION). I would like to remember that the conclusions should be fully coincided with the findings of the paper. The statement that “the cellulose content is proved to increase in the bamboo surface in chemical composition” does not agree with the research results presented in Table 1 (line 196 in the revised version).
Response: We are very grateful to Reviewer for reviewing the paper so carefully. Thank reviewer for giving us positive and careful suggestions. It is a writing mistake. It has been revised in our revised version.
Author Response File: Author Response.doc
