Facile Fabrication of High-Performance Superhydrophobic Reusable Oil-Absorbing Sponges
Round 1
Reviewer 1 Report
In this work, Sugurbekova and coworkers reported a RGO and MgFe2O4 functionalized sponge material with superhydrophobic property that can be applied in absorption of oil and organic solvents. The absorbing results indicate that the sponge composite material has good mechanical and water repellent properties and can be reused multiple cycles. This material could be of interest for researchers in the area of water treatment and environmental engineering. Therefore, this manuscript can be published after concerns below being addressed.
1. In page 4, formula 2, the authors stated that ‘m2 and m1 are the masses of the sponge before and after oil absorption’ which will give m2-m1 a negative value. I believe it should be m1 and m2 corresponding to before and after absorption respectively.
2. Measurement of contact angle was adopted as the main approach to show the superhydrophobic feature. It would be a more straightforward way to weigh the sponge before and after soaking into water and compare the mass difference, because there might be a small amount of water trapped in small pores.
3. In the calculation of separation efficiency, how does the author confirm the mass difference n2-n1 is totally contributed by oil without any water? Characterization of water in the sponge after absorbing needs to be conducted.
4. Characterization of leftover solution after absorbing tests should be carried out to show whether leaching of RGO or MgFe2O4 exists.
5. Please add experimental details of the continuous separation test (fig 10) into the experimental section.
Author Response
Dear Reviewer,
We attached doc with reply.
Best regards,
Authors
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This manuscript developed new superhydrophobic magnetic polyurethane (PU) sponges functionalized with reduced graphene oxide (RGO), MgFe2O4 nanoparticles, and silicone oil (SO) as a selective and reusable sorbent for the purification and separation of wastewater from oils and organic solvents. From the contents reported in this paper, the study has achieved good results. There are still several issues need to be solved:
1. In general, contact angle measurements should be repeated several times.
2. Can the authors stain the oil or water to enhance the observation of the separation effect in Figure 6? There are some articles on surface wettability modification as a reference for staining:
[1] Optics & Laser Technology 168 (2024) 109829.
[2] Chinese Optics Letters, 2021, 19(8):082201.
[3] Optics & Laser Technology, 2018, 102:25–31
3. It would be better to increase the cycle times of the absorption cycle test in Figure 7 for a consideration of practical use.
4. It seems that part of Figure 8 is cut off. Please make some adjustments.
5. In Figure 10, the sub-figures in the same series need to be marked with boxes to avoid misunderstanding.
Based on my comments, I will accept this manuscript for publication after a minor revision.
Minor editing of English language required.
Author Response
Dear Reviewer,
We attached doc with reply.
best regards
Authors
Author Response File: Author Response.pdf
Reviewer 3 Report
The paper entitled “Facile fabrication of high performance superhydrophobic reusable oil absorbing sponge” reported effective oil separation from water by using superhyrolophobic polyurethane sponge. The results were remarkable, but they are almost same with their previous paper (Int. J. Environ. Sci. Tech., 2021, 19, 8491). This paper seems to be added a demonstration (Figure 10) to their previous paper, meaning that this paper does not include new scientific points. Thus, this paper is not suitable to this journal.
Line 96: the preparation method seemed not matched with figure 1.
Line 161: scale bars are missed in Figure 2.
Line 168: What is the origin of superhydrophobicity?
Line 183: what were the roll off angles of the modified sponge?
Line 194: It should be Figure 4.
Line 320: Why did Table 1 exclude reference 29?
Line 322: What is the difference from ref 29?
Line 338: the authors said “the sponges can be controlled by magnet”. Where is the data?
The authors are using “wt.%”, “wt %”, “% wt” and “wt%”. They should be unified.
“figure” should be “Figure”.
The authors are using two ways to mention percentage (%); XX.X % and XX,X %. They should be unified.
Line 54: Zhu others
Line 93: There is “First” without “Second”.
Line 96: 50 ml
Author Response
Dear Reviewer,
We attached doc with reply.
best regards
Authors
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
The authors replied that “Silicon oil AS 100 is much cheaper than PDMS and has good mechanical properties. Therefore, the authors decided to study Silicone oil AS 100 as a cheap and durable type of superhydrophobic material.” This point including the material design should be mentioned in the introduction of this paper.
The author mentioned Silicon oil AS 100 increased the absorption capacity compared to PDMS at line 372, although they seemed just a binder between PU and RGO. The authors must explain how Silicon oil AS 100 increased the absorption capacity.
Line 53: Zhu and the others
Line 96: 50 mL
Line 197: 0.0°
Line 197: 0.3°
Author Response
Dear Reviewer,
The authors have attached a document with responses to comments.
Best regards,
Author's
Author Response File: Author Response.pdf
