Zinc Complex Derived from ZnCl2-Urea Ionic Liquid for Improving Mildew Property of Bamboo
Round 1
Reviewer 1 Report
„Zinc complex derived from ZnCl2-urea ionic liquid for improving mildew property of bamboo” is quite an interesting paper. However, in my opinion, it requires some corrections before publishing.
First of all, the paper requires thorough linguistic corrections (English).
Introduction
- Line 33 – please explain why mildew resistance is so important for bamboo-based products.
- Line 36 – “ray” treatment – what kind of radiation do the Authors mean? Please, add the information.
Materials and Methods
Please, add some more details about the material and procedures applied in the research:
- How old was bamboo used for the study? What were its dimensions?
- Why was the temperature of 80 ℃ applied for drying?
- What was the time of ILs preparation in a water bath?
- How long were the bamboo blocks submerged in the treatment solution?
- There is an AIV value missing in Table 1 (first column) – this value is necessary to calculate MCE according to Equation 1 given in the paper.
- How were the samples analysed with SEM – were they coated?
Results
- The labels in the SEM images in Figure 2 do not match the labels given in the figure description.
- There are only SEM images of the treated samples – it would be good to show their appearance to assess if the treatment fulfils the requirements of aesthetics if we would like to consider the proposed new treatment method as useful in practice.
- Line 101 – the Authors claim that the zinc complexes are of nanometre level, but it is not particularly in line with the SEM pictures presented. What exactly the Authors mean as “zinc complexes”?
- How can the Authors explain the difference in Zn and Cl content in particular treated samples (EDS spectra presented in Figure 3, Table 2)?
- Lines 132-134 – this statement requires a literature reference; the same applies to the next sentence (lines 134-136) about the band at 2240 cm-1.
- Could you explain the origin of the bands at 2931 and 2849 cm-1 in the treated samples and the difference in this region in comparison with untreated bamboo?
- Please, mark the 3424 cm-1 band in Figure 4.
- Line 143 – Why? Please, explain why mildew is so dangerous for bamboo products.
- We cannot mention the antibacterial effect of Zn when we discuss its antifungal activity (line 159-160) – fungi and bacteria are different organisms. Please, explain the antifungal effectiveness of Zn and provide suitable literature reference.
Conclusions
- If we consider the proposed method as a novel and effective approach to prolong the service life of bamboo, shouldn’t we know the results of its anti-fungal resistance after some leaching or ageing tests, to evaluate the long-term effectiveness of the treatment?
- Please, name the examples of the possible application of bamboo treated with the proposed method.
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This paper describes a new treatment for preparing mildew-proof bamboo. The method seems to be simple. easy and efficient to fabricate a nano-Zinc complex coated bamboo surface by immersing bamboo in zinc chloride (ZnCl2)/urea ionic liquid (IL) for some time. Methods for characterization of microstructures are powerful and correct. The resulting nano-Zinc complex coated bamboo surface exhibited excellent anti-mildew properties.
Minor modifications to improve the quality of the presentation
Abstract: The last sentence should be modified.100% resistance is not possible. Figure 6 shows that the resistance of U2-t2 is better than U2-t3 and at least 28 days, but it is very likely that time, humidity temperature and other external factor can finally affect the bamboo surface for infection.
Line 61: “ultrasonically washed several times with deionized water and ethanol”, Indicate the number of times with water and then ethanol or, if so, the concentration of the hydroalcoholic solution
Line 72-73: “According to previous work”. Is that previous work published? Is there any reference for that previous work? If so, please indicate it, otherwise, delete that expression. One of the main conclusions of this work is determining that optimal ratio 1:2. If the ration is already known, the content of this paper lose significance
Line 81: “each fungus”. Indicate which ones.
Figure 2: Replace labeling (g) by (d) in the U2-t3 micrograph; Replace k by K at (a) micrograph.
Lines 106-108: “When the processing time was extended to 3h, the nano-Zinc complex layer becomes more uniform, and the shape of the nano-Zinc complex began to dissolve into a ball”
The layer is more uniform, but the authors claim that the coating is dissolved in a ball. Please clarify, I cannot observe this sort of “solution”.
Figure 3: The different Cl/Zn ratio observed at Figure 3 for the respective coatings should be justified. The ratio Zn/Cl is maximal at the U2-t2 treatment.
Table 2: N is only found at U2-t3. This N should come from urea. Can authors briefly discuss that point and possible justification. Is that N the reason of the lower efficiency of the coating. Is the amount of ZnO formed proportional to the N released?
Lines 146-147 (and later on, including legend of figure 6): Bacterial names in italics, please.
Line 148: Please, clarify the relationship between grade for infection degree (GID) and the average infection value (AIV). The method for calculation of GID values, 4, 2 or 3 is not described. In general, the paragraph (lines 150-163) with details about day of infection, bacterial strain used for infection and time of resistance is a little bit confused. I suggest some re-writing of that part.
Author Response
Please see the attachment
Author Response File: 
Author Response.doc
Reviewer 3 Report
The manuscript presents valuable data related to wood protection.
It is well-written, experimental results are clearly presented and discussed.
It can be accepted for publication in its present form.
Author Response
Please see the attachment.
Author Response File: Author Response.doc
Round 2
Reviewer 1 Report
The manuscript was improved according to the comments and suggestions. However, it still requires some linguistic corrections. Moreover, because the aesthetics of treated bamboo is not particularly satisfactory (an apparent “cloudy” coating of Zinc complex on its surface – Figure 2), I do not think that this kind of treatment will be useful for bamboo intended for decoration or furniture making. It should be clearly stated in the manuscript. I also suggest mentioning that the applied treatment was not tested for its antifungal effectiveness after artificial ageing or washing, and that these issues require further study before the proposed treatment method could be introduced to the industry.
Author Response
Please see the attachment.Author Response File: Author Response.doc
