A Hybrid Superhydrophobic/Hydrophilic Surface Based on SiO2 Nanoparticles over a Clay Substrate for Enhanced Dew Yield Potential
, Jackeline Iturbe-Ek, Oscar Martínez-Romero, Alex Elías-Zúñiga and Alan O. Sustaita *Round 1
Reviewer 1 Report
In this paper, the author described a fabrication method of superhydrophobic-hydrophilic surface on clay tile by SiO2 nanoparticles(NPs). SiO2 NPs were hydrophobically modified by OTS to fabricate a superhydrophobic surface. Then, untreated SiO2 was patterned on the superhydrophobic surface to produce a superhydrophobic-hydrophilic mixed surface. This paper has conducted extensive experiments and has many analyzes, but there are many shortcomings in important areas. Therefore, I believe that in order for this thesis to be accepted, it is necessary to supplement the following contents.
The notes are listed below.
- A mix use of the word SHPho and SPHo. And a typo at the beginning of section 3.5. I don't know why the ‘h’ is inserted in italics in the caption of Figure 9. A typography check is required as a whole.
- How are 10-20 nanometers filtered out with a 0.45 micrometer filter?
- The following sentence is in the introduction: “Biomimicry of this creature and other living things with similar attributes has allowed for the development and engineering of surfaces with dewetting, self-cleaning, water harvesting and superhydrophobic properties”
The authors need to refer to the following recent paper on superhydrophobic/superhydrophilic patterning.
Lee, J. W., Kim, K., Ryoo, G., Kim, J., Kumar, J. V., & Hwang, W. (2022). Super-hydrophobic/hydrophilic patterning on three-dimensional objects. Applied Surface Science, 576, 151849. - Homogeneous roughness is discussed in Figure 4, but it cannot be judged because there is no scale bar.
- There is no information on the size of the hexagonal hole of the masking. In Figure 9, there is no scale bar in the photo, so it is impossible to estimate its size. And the picture quality is very poor.
- In Figure 9, The background color is white, but the water droplets are transparent, so the wet part is almost invisible. It is recommended to dye the water droplets red or blue.
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Dear Authors,
your interesting paper describes the coating of clay roof tiles by silica nano particles with and without hydrophobic treatment with octadecyltrichlorsilane to achieve hydrophobicity and hydrophilicity simultaneously.
Some completions should be done:
Introduction
- A Superhydrophilic/superhydrophobic surface is reported in the following paper, which should be added: Superhydrophobic−Superhydrophilic Micropatterning on Flowerlike Alumina Coating Film by the Sol−Gel Method, Tadanaga et. al. Chem. Mater. 2000, 12, 3, 590–592 .
- Paragraph 3: “SPHo” (I think you mean SHPho), but this short cut is only introduced at the end of the introduction!
Experimental:
2.5 “samples”…make clear, what you are talking about: The NPs? The clay? The coated clay? This belongs not only to 2.5, please check this in your whole manuscript!
2.7 First sentence: SiO2 NPs !
Last sentence: powdered!
2.9 characterization of “all samples”…better: “of the coated and uncoated clay”!
Results
3.1 third sentence: “OTS carbon chains”, these are “hydrocarbon chains” or “long chain alkyl groups”
3.3: Fig.3: For comparison, the CA of clay, coated with non-treated SiO2 NPs would be interesting! Can you add this to the figure?
What do you mean with “surface dried”? Looking to table 1 its clear, that all coated samples are dried at 80°C. So in your paper you only have to distinguish between coated and uncoated surfaces! In the manuscript “surface dried” or “furnace dried” should be removed. Its more easy to understand, if you just talk about coated and uncoated clay!
Fig.4: The scaling and the z-range is missed, the pictures are too small, the coloration and/or resolution are not the best.
Fig. 5 “surface dried samples”…please exchange by uncoated and coated clay. Can you add the roughness of clay, coated with non-treated SiO2 NPs?
3.3: Fig 6 You don’t say anything about the two peaks of the OTS at about 600 cm-1! Why are these peaks not to find for the OTS treated NPs?
3.5. First sentence:…..section “3.2”…I think you mean “2.3”?
Fig8: What’s the size of the hexagons and the distance between them?
Supplementary Information:
S1: The word “nitrogen” is missed !
S2:a) the z-range and the scaling is missed!
Here the blue box marks the HPo segment, the red box the HPi segment, but in Fig9 it’s the opposite, please make it uniform!
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
In the revised version of this paper, it was judged that all of my revision requirements were resolved. In my opinion, this paper is now ready for publication.
