Effects of Changes in Biopolymer Composition on Moisture in Acetylated Wood
, Maria Fredriksson 4, Erni Ma 2, Jinzhen Cao 2, Ramūnas Digaitis 4 and Lisbeth Garbrecht Thygesen 3Round 1
Reviewer 1 Report
A very interesting study, well presented and discussed.
One aspect that I felt was needed is the information about calculation method for the ACc, AHc and ALc values, used in figures 3 and 6. Did you assume some function of the level of hemicellulose/lignin removal, or some function of level of acetylation, based on for example weight percent gain? A general formula would be useful, either in the results text near Figure 3 or earlier, in the method section.
In the equation for accessible hydroxyl groups, you refer to three parameters which you mention, but do not clarify. what is the difference between Mred and Mor? Is this given in the supporting paper [11]? It is not sufficient to expect the reader to download this just to interpret your results. In paper [11] there is a complex discussion of the need to use Mor and Mred values to calculate EMCr values, but none of this supporting information is available to assist the reader of your text. I suggest that you add a sentence or two to clarify that EMCr presents a better evaluation of moisture per wood substance (not modified wood substance) and that you used Mred for the deuterium exchange experiment for the same reason. Readers may find it useful to know how you calculated Mred values based on the thin slivers of material that you loaded into DVS machine. An equation would be appropriate.
When using the various parameters in the above equation, i notice the M is capital letter, and the or, red or ex are subscripts. Can you match this in your manuscript to make it easier to read these in the body text please?
In the NMR methodology, you use the acronym CPMG without explanation, please add the full name for clarity.
Also in the NMR method section, the final paragraph is very short, detailing one sample, two specimens and three replicates. Could you elaborate please? You have been using 'specimen' earlier in the text to mean the individual pieces of wood, so what do you mean by sample? and what kind of replication? was a singe piece of a single specimen run three times, or was a single piece from two specimens both run three times (giving six replicates?) or some other combination. It was not clear to me.
Other comments are simply relating to spelling or grammar, or meaning of sentences.
page 1, line 36-37. You sau "The aplicability of wood and wood products is consequently challenged by too rapid moisture changes." Do you need 'too rapid' in this sentence? If so, why? This was not clear to me. Surely wood is challenged by slow moisture changes too - e.g. decay is just as likely in slowly changing conditions, and dimensional change still occurs even when moisture content changes slowly.
page 2line 57, suggest you use 'the' not 'a', in the phrase "that the number of accessible hydroxyl groups..."
page 3, line 89, suggest you alter the sentence about magnetic stirrer. e.g. "... stirring was provided by a magnetic stirrer" or "...for 1 hr using a magnetic stirrer to ensure circulation" or similar
page 6, line 187, the clause 'by about 90%' could be in brackets where it is, or needs to move to the next comma to make better sense ("lower hydroxyl accessibility than control wood by about 90%,").
page 9, line 247, 'markedly' should be 'marked'.
page 9 line 256, "affinity to water, as implied by ..." note this is also a very long sentence. could cut in half at line257, after (figure 4).
page 9 line 268, is it useful to add 'within wood' to the sentence so it is clear where the 'pools of water' are?
Otherwise, this is a very well presented piece of work. Well done.
Author Response
To reviewer 1：
- Comment: A very interesting study, well presented and discussed.
Response: Thanks for your kind affirmation for our study.
- Comment: One aspect that I felt was needed is the information about calculation method for the ACc, AHc and ALc values, used in figures 3 and 6. Did you assume some function of the level of hemicellulose/lignin removal, or some function of level of acetylation, based on for example weight percent gain? A general formula would be useful, either in the results text near Figure 3 or earlier, in the method section.
Response: Thanks for your kind comment. A general formula has been added in the method section. Please refer to page 5, line 158-170.
- Comment: In the equation for accessible hydroxyl groups, you refer to three parameters which you mention, but do not clarify. what is the difference between Mred and Mor? Is this given in the supporting paper [11]? It is not sufficient to expect the reader to download this just to interpret your results. In paper [11] there is a complex discussion of the need to use Mor and Mred values to calculate EMCr values, but none of this supporting information is available to assist the reader of your text. I suggest that you add a sentence or two to clarify that EMCr presents a better evaluation of moisture per wood substance (not modified wood substance) and that you used Mred for the deuterium exchange experiment for the same reason. Readers may find it useful to know how you calculated Mred values based on the thin slivers of material that you loaded into DVS machine. An equation would be appropriate.
Response: Thanks for your nice suggestion. We have changed the equation so it is more clear how the hydroxyl accessibility is based on the change in dry mass after deuterium exchange and put in relation to the dry wood mass, i.e. discounting the added mass of the acetylation. Please refer to page 4, line144-154. In addition, we have also specified the moisture content calculation standard by correcting it for the increase in dry mass caused by the acetylation, also taking into account the mass loss of the pyridine control specimens. That is the EMCr as presented in previous researches. Please refer to page 4, line 119-121. Based on the new and more accurate calculation standard, the moisture content and hydroxyl accessibility can be attained in the new manuscript.
- Comment: When using the various parameters in the above equation, i notice the M is capital letter, and the or, red or ex are subscripts. Can you match this in your manuscript to make it easier to read these in the body text please?
Response: Thanks for your kind comment. We have changed the equation and modified the writing of parameters and make it more accurate and easier for readers to read these in the text. Please refer to page 4, line 144-154.
- Comment: In the NMR methodology, you use the acronym CPMG without explanation, please add the full name for clarity.
Response: Thanks for your nice comment. The full name has been added in the NMR methodology. Please refer to page 4, line 115. Besides, we have added more details in this section to give readers more practical information. Please refer to page 3-4, line 103-131.
- Comment: Also in the NMR method section, the final paragraph is very short, detailing one sample, two specimens and three replicates. Could you elaborate please? You have been using 'specimen' earlier in the text to mean the individual pieces of wood, so what do you mean by sample? and what kind of replication? was a singe piece of a single specimen run three times, or was a single piece from two specimens both run three times (giving six replicates?) or some other combination. It was not clear to me.
Response: Thanks for your kind comment. In this study, sample was used to describe quantity of bulk material or irregular material that has been selected by some sampling process. Specimen means the individual pieces of wood. During LFNMR analysis experiment, one replicate consists of two specimens, and the replicate information is further shown in Table 1 in the manuscript. To make it more clear, we have also modified the sentence to elaborate it. Please refer to page 4, line 122-124.
- Comment: Other comments are simply relating to spelling or grammar, or meaning of sentences. page 1, line 36-37. You sau "The aplicability of wood and wood products is consequently challenged by too rapid moisture changes." Do you need 'too rapid' in this sentence? If so, why? This was not clear to me. Surely wood is challenged by slow moisture changes too - e.g. decay is just as likely in slowly changing conditions, and dimensional change still occurs even when moisture content changes slowly.
Response: Thanks for your nice comment. We agree with your opinion and we have removed the “too rapid” and changed the expression into "The aplicability of wood and wood products is consequently challenged by moisture changes." Please refer to page 1, line 37.
- Comment: page 2line 57, suggest you use 'the' not 'a', in the phrase "that the number of accessible hydroxyl groups...”
Response: Thanks for your kind suggestion. We have modified the sentence according to your suggestion. Please refer to page 2, line 57.
- Comment: page 3, line 89, suggest you alter the sentence about magnetic stirrer. e.g. "... stirring was provided by a magnetic stirrer" or "...for 1 hr using a magnetic stirrer to ensure circulation" or similar
Response: Thanks for your nice suggestion. We have modified the sentence according to your suggestion. Please refer to page 3, line 91-92.
- Comment: page 6, line 187, the clause 'by about 90%' could be in brackets where it is, or needs to move to the next comma to make better sense ("lower hydroxyl accessibility than control wood by about 90%,").
Response: Thanks for your kind suggestion. We have modified the sentence and put the “by about 91%” into brackets. Please refer to page 7, line 222.
- Comment: page 9, line 247, 'markedly' should be 'marked'.
Response: Thanks for your nice comment. To give more accurate explanation, we have rewritten this section colored in green. Please refer to page 11, line 281-284.
- Comment: page 9 line 256, "affinity to water, as implied by ..." note this is also a very long sentence. could cut in half at line257, after (figure 4).
Response: Thanks for your kind commet. We have rewritten the sentence and made it more easy to read. Please refer to page 11, line 289-292.
- Comment: page 9 line 268, is it useful to add 'within wood' to the sentence so it is clear where the 'pools of water' are?
Response: Thanks for your nice comment. We have added the “within wood” to the sentence, so it’s clear where the 'pools of water' are. Please refer to page 11, line 303.
- Comment: Otherwise, this is a very well presented piece of work. Well done.
Response: Thanks for your kind affirmation for our study.
Author Response File: 
Author Response.doc
Reviewer 2 Report
The manuscript is of high scientific quality.
Author Response
To reviewer 2：
- Comment: The manuscript is of high scientific quality.
Response: Thanks for your nice affirmation for our study.
Author Response File: Author Response.doc
Reviewer 3 Report
Dear Authors,
I have read the article entitled „Effects of changes in biopolymer composition on moisture in acetylated wood".
This is a straightforward study. This study investigated how changes in the biopolymer composition in wood as well as acetylation of accessible hydroxyls affect the hydroxyl accessibility, moisture content and water distribution in the material.
The subject of the study falls within the scope of the Journal. The title and abstract reflect the content. The introduction initiates the reader on the subject and a well-selected list of references was used (46 references). All tables and figures are mentioned in the text. Explanations are given for a better understanding of the subject.
The paper is ready for publication. I have only two suggestions:
Page 2/line 72: ...”using the following treatments”.
Perhaps a sequence of the steps may be compiled in a tabel format for a better overview of the treatments described in this section.
Page 3: The same approach or by using a diagram for a better visualisation of the information described in the text would be ideal, if possible.
I hope my revision was of help.
Author Response
To reviewer 3：
- Comment: This is a straightforward study. This study investigated how changes in the biopolymer composition in wood as well as acetylation of accessible hydroxyls affect the hydroxyl accessibility, moisture content and water distribution in the material.
The subject of the study falls within the scope of the Journal. The title and abstract reflect the content. The introduction initiates the reader on the subject and a well-selected list of references was used (46 references). All tables and figures are mentioned in the text. Explanations are given for a better understanding of the subject.
Response: Thanks for your nice affirmation for our study.
- Comment: Page 2/line 72: ...”using the following treatments”. Perhaps a sequence of the steps may be compiled in a tabel format for a better overview of the treatments described in this section.
Response: Thanks for your nice suggestion. To give readers a better overview of the treatments described in the methods section, we have added a schematic diagram (Figure 1 in the revised manuscript) and given an illustration , please refer to page 2, line 72-73, page 3, line 84-85.
- 3. Comment: age 3: The same approach or by using a diagram for a better visualisation of the information described in the text would be ideal, if possible.
Response: Thanks for your nice suggestion. A schematic diagram (Figure 1 in the revised manuscript) has been added for a better visualisation of the information described in the text, please refer to page 3, line 84-85.
Author Response File: Author Response.doc
