Development of Ultrasonic Pulsed Plasma Jet Source for Remote Surface Treatment

Round 1

Reviewer 1 Report

The comments are in the attached file.

Comments for author File: Comments.pdf

Author Response

Dear Revier1:   I will reply to you as follows.
The number of files is 1.

Lines 63 - The sentence “As the constant flow velocity increased…” It's not clear what you mean. If the speed is constant, then it does not increase. If you think that the value of constant speed is changing, then rephrase the sentence.

→Lines 63 - 64.
   I removed "constant" and replace with correct wording.

Line 111 “… water droplet resting on solid surface…” - What solid material did you use in the experiments? When plasma treatment is performed, it also depends on the type of material you use. Add the information about the material.

→Line 111. I Add information on copper plates.

Line 143 shock diamonds - On line 203 you give an explanation of what it is. Move this information to line 143.

→Lines 143-144.  I Moved the information to line 143.

Line 152 and 196 - These lines have the same sentences.

→Lines 153-154
　Line 196 was deleted because it was duplicated.

Line 243 - What does n=3 mean?

→Lines 240-242
　It means 3 measurements.

Typography:

Line 122, 123, 178, 179, 184, 185 - Physical units are written in italics. You have some written that way, others not.

→ I Unify the style to Cambria Math.

Line 124 - In the formula (1) you have r', but in the text r. What is correct?

→I corrected it to 'r'.

Conclusion:

Line 286 and 293 - On line 286 you write about nitrogen and on line 293 also, but the contact angle change is different and on line 293 you also mention helium. Which information is correct?

→It talks about nitrogen plasma, so it is not about helium.
　The correct information has been corrected. We have corrected the information to be correct.

Do you think the device will have application use if the change in contact angle compared to the conventional device is not significant

→Nitrogen supersonic plasma is used for short-distance processing, while helium supersonic plasma is used for long-distance processing.
　It is clear that nitrogen supersonic plasma is effective in improving hydrophilicity
　We believe that the application of this device is possible depending on the distance of the object
　We believe that the application is possible depending on the distance of the object

Sincerely,

Takashi Ohta

Okino lab, FIRST, Tokyo Institute of Technology

Address: 4259-J2-32, Nagatsuta, Modori-ku, Yokohama 226-8502, Japan

Tel, Fax: +81-45-924-5689

Email: [email protected]

 

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript describes the basic characteristics of a supersonic pulsed plasma jet at low temperature and atmospheric pressure and the results of its surface hydrophilization are discussed.

 Comments

 1-The contact angle measurement should be more detailed. It is well known that contact angle can change after plasma exposure due to ageing process and also depend on the chemical composition of the solid used.

 2-The contact angle measurement need to be perform on a solid surface without plasma using the same gas flow rate to observe surface charged due to gas velocity, therefore the results can be compared.

 3-Fig. 5 shows the relationship between irradiation distance and hydrophilic effect. At the working distance over 20 mm, for N₂, air and CO₂ plasma gas, all results are quite similar. Therefor it is quite difficult to conclude on the hydrophilicity effect. Farther experiments by Optical Emission Spectroscopy analysis should be performed to investigate reactive plasma species in the plasma jet against distance.

Author Response

Dear Reviewer2

I will reply to you as follows.
The number of files is 1.

1- Contact angle measurements need to be more detailed. It is known that the contact angle after plasma irradiation changes over time and also depends on the chemical composition of the solid used.

→Thanks for your comment, I added the information on the copper plate in line 111.

 2- Contact angle measurements should be performed on a solid surface without plasma at the same gas velocity to observe surface charging due to gas velocity, so that the results can be compared.

→Thank you for your comment. In this paper, we evaluated how much the contact angle changes at each irradiation distance for different gas types. We believe that in the future we need to compare the results on a solid surface without plasma at the same gas flow velocity.

 3-Figure 5 shows the relationship between irradiation distance and hydrophilic effect; at distances of 20 mm or more, the results are almost the same for N2, air, and CO2 plasma gas. Therefore, it is very difficult to conclude about the hydrophilic effect. More distant experiments with optical emission spectrometry are needed to investigate the reactive plasma species in plasma jets versus distance.

→Thanks for your comments. In this paper, we found that nitrogen supersonic plasma is effective in improving hydrophilicity for short-distance treatments and helium supersonic plasma for long-distance treatments. To verify the hydrophilic effect at a long distance, we would like to measure the emission spectra of the plasma of each gas species, observe atomic and molecular lines originating from the gas in the plasma of each gas species, and confirm that the arrival distance of the excited and active species has been extended

Sincerely,

Takashi Ohta

Okino lab, FIRST, Tokyo Institute of Technology

Address: 4259-J2-32, Nagatsuta, Modori-ku, Yokohama 226-8502, Japan

Tel, Fax: +81-45-924-5689

Email: [email protected]

 

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

No comments