Evaluation Test of NO Degradation by Nano-TiO2 Coatings on Road Pavements under Natural Light
Round 1
Reviewer 1 Report
The article has been written nearly two years ago. The recent references on the work are missing.
NO is gas and also hot when emitted from the vehicle, it will go upward, will there be any benefit of painting the pavement. In one hour where will it go, is there a method where they are being captured and kept for one hour to get degraded?
Also, this nano TiO2 will be there in the rain and with time it will erode and thus will go into the atmosphere and water bodies in an uncontrolled way. The photocatalytic properties of Nano TiO2 is known for decades.
They are also saying that already 5 KM road is made in china using this.
Thus, there is not much scientific importance in this work, and can be rejected.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
Introduction is not clear why TiO2 is needed for the pavement, what are the advantages of TiO2 for this applications and how to use it.
Section 2 (Theoretical analysis) should be merged with introduction some parts of this should be in Methodology section
The mixing process is very complicated in the text form at this point Figure as flowchart is need.
Please check the title of Table 2
Figure 4(b), schematic or drawing is preferred (If you want to use photograph the labels have to be clear.
Figure 6, please change to color figure
The SEM along with EDS images of TiO2+acrylic are essential in this paper, since this is the evidence of coating and these will help to explain Figure 8
Figure 2 can be moved to after Figure 8
Author Response
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Reviewer 3 Report
Dear Authors,
you descibe the addition of photocatalytic active TiO2 to road pavement marking for reducing NOx in the cities. It is clearly shown, that the acrylic emulsion with 2 to 6% TiO2 reduces NOx much faster (about 90% in the setup) than the emulsion without TiO2 (about 25% in the same setup).
Taking into account the blank value, the reduction of NOx in the setup used differs between 65 and 71% (during one hour) for the samples with 2, 3, 4 ,5, and 6% TiO2. These variations may be in the experimental error, which is not given!
Did you repeat the measurments for the different sample compositions or did you measure each composition only one time????
To discuss these variations in detail and explain by assumptions (agglomeration of TiO2) without any confirming investigtions, makes no sence.
The experimental part has to be explained more exactly:
Especially the preparation od the samples:
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What is XZ-Ti01 ? Where does it come from? Company? Particle size? Pure Anatase? Or also Rutile?
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What kind of „acrylic emulsion“? Where does it come from?
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What kind of „additives“
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How did you „stirr“?
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What kind (plastic, glass etc..seems to be plastic, line 150?) of substrate did you coat? Size of the platte (line 122: 30x18x20cm?)
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How did you apply the emulsion on the plate and how much?
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Is there a drying procedure? Weight loss during drying?
Line 130 What is AVL?
Line 133 What kind of glass (soda lime? Borosilicate? Quartz glass?) did you use? Thickness?
Fig.4 „nitrous“ what do you mean? N2O? N2O2...please specify! Or is it really NO (line 158/159)?
Line 143 11:30 – 2:30 outside? In which city? Did you measure intensity (W/m2)?
Line 328 You talk about „six groups of coating materials“. In the manuscript one can find only 6 different TiO2 concentrations!...but not 6 groups...what do you mean?
Table2 is not correct, % are missed for 2,3,and 5! ppm??? this belongs to NO? You have to make this clear!
Line 142 „1.5-1.8 mm thickness“ The application conditions may influence porosity of the coating, which means diffenrent surface areas, which should result in different decomposition efficiencies!
SEM investigation would be a suitable method to compare porosities of the samples and may be also to show the possible „agglomeration“ of the nano-TiO2?
Line 319: point 1-4
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What will you wash? The nano-particles?
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Add a dispersant...to the acrylic emulsion?
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Unique drying process...for the nanoTiO2 or the applied coating?
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Ultra sonic cavitation...how did you do? you should compare to your procedure!
Please make this points clear!
In the discussion you talk about agglomeration, which could be a possible explanation, but no investigations, like SEM e.g., are done, which could prove this assumption.
The decomposition efficiency for all TiO2-containig (2-6%) samples is really good (65-71%), would be also intersting to know, if 0.5 or 1 % of TiO2 is also in this range?
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
can be accepted
Author Response
English language and style
( ) Extensive editing of English language and style required
(x) Moderate English changes required
( ) English language and style are fine/minor spell check required
( ) I don't feel qualified to judge about the English language and style
Comments and Suggestions for Authors
can be accepted
Re/ Thanks for your encouragement. We will polish the language and keep revising the manuscript until it meets the requirements of Journal of Coatings.
Reviewer 3 Report
Dear Authors,
if I look to the revised manuscript, there are more mistakes than before:
The size of the plate is still 30x18x20cm (line 123), but this is a box!
Now the auhors mix an acrylic suspension with anatase and NO gas cylinders (line 119), that's nonsence!
How did you stirr? With which machine?
How did you coat? How did you apply the coating mass on the plastic plate?
In Fig.4 "nitrous" and "AVL" is not explained, like I suggested! AVL is a company in Graz, Austria, this has to be noted!
"wash the used coating materials" (line326)... what are the "materials"???
and again, you don't have six different groups of coating materials, you have six different TiO2-concentrations!
I can only repeat, that the function of the TiO2-bearing coating is clearly shown, yes, but to discuss the very small differences in efficiency for the 5 TiO2 concentrations without any confirming investigations make no sence, makes no sence.
I'm not willing to spent my time with such unprofessional work any more.
Author Response
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Author Response File: Author Response.pdf
Round 3
Reviewer 3 Report
Dear Authors,
the mistakes are corrected now, the main point (reduction of NOx by TiO2 in pavement marking) is clear.
Author Response
- Open Review
English language and style
( ) Extensive editing of English language and style required
( ) Moderate English changes required
(x ) English language and style are fine/minor spell check required
( ) I don't feel qualified to judge about the English language and style
Re/ Thanks for your encouragement. We will keep polishing the language to satisfy the requirements of Journal of Coatings.
