scholarly journals Novel atmospheric pressure plasma device releasing atomic hydrogen: reduction of microbial-contaminants and OH radicals in the air

2007 ◽  
Vol 40 (2) ◽  
pp. 501-509 ◽  
Author(s):  
Hideo Nojima ◽  
Rae-Eun Park ◽  
Jun-Hyoun Kwon ◽  
Inseon Suh ◽  
Junsang Jeon ◽  
...  
2018 ◽  
Vol 13 (3) ◽  
pp. 155892501801300
Author(s):  
Carrie Cornelius ◽  
Marian McCord ◽  
Mohamed Bourham ◽  
Peter Hauser

Nonwoven polypropylene and cotton fabrics are grafted to a vinyl quaternary compound using atmospheric-pressure plasma. Two different atmospheric plasma devices are used -the NCAPS (North Carolina Atmospheric Plasma System), a dielectric barrier discharge device created by North Carolina State University, and a plasma device from APJeT® Inc. The addition of additives such as Mohr's salt, potassium persulfate, and diacrylates are assessed to see if graft yield can be increased. Acid dye tests, SEM, and XPS reveal successful grafting of the vinyl quaternary compound. A combination of all four additives is found to yield the highest graft yields and greatest uniformity.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Samed Ayhan Özsoy ◽  
Safiye Meriç Acıkel ◽  
Cem Aydemir

Purpose The surface energy of the printing material can be increased to desired levels with different chemicals or methods. However, the important thing is that the surface properties of printing material are not affected negatively. In this way the aim of this paper provide that the surface properties of matte and glossy coated paper is improved by the argon containing atmospheric pressure plasma device because the plasma treatment method does not occur surface damaging on the papers. Design/methodology/approach In experimental studies, test samples cut from 160 mm × 30 mm in size from 115 g/m2 gloss- and matt-coated papers were used. The plasma treatments of paper samples were carried out with an argon containing atmospheric pressure plasma device of laboratory scale that produces plasma of the corona discharge type at radio frequency. The optimized plasma parameters were at a frequency of 20 kHz and plasma power 200 W. A copper electrode of length 12 cm and diameter 2.5 mm was placed in the centre of the nozzle. Findings Research findings showed that the surface energies of the papers increased with the increase in plasma application time. While the contact angle of the untreated glossy paper is 82.2, 8 second plasma applied G3 sample showed 54 contact angle value. Similarly, the contact angle of the base paper of matt coated is 91.1, while M3 is reduced to 60.4 contact angles by the increasing plasma time. Originality/value Plasma treatment has shown that no chemical coating is needed to increase the wettability of the paper surface by reducing the contact angle between the paper and the water droplet. In addition, the surface energies of all papers treated by argon gas containing atmospheric pressure plasma, increased. Plasma treatment provides to improve both the wettability of the paper and the adhesion property required for the ink, with an environmentally friendly approach.


Author(s):  
Naoki Shirai ◽  
Takuma Kaneko ◽  
Yuto Takamura ◽  
Koichi Sasaki

Abstract We have shown that measuring the surface tension is a useful scheme to examine the plasma-liquid interface in real-time. The surface tension was measured using a method based on the dispersion relation of an acoustic capillary wave excited on the water surface. The surface tension gradually increased with time, when the water surface was irradiated with the outside region of the spatial afterglow of an atmospheric-pressure plasma. The Marangoni effect associated with the localized increase in the surface tension was observed during the plasma irradiation. The surface tension decreased after the termination of the discharge. A correlation was found between the transient decrease in the surface tension and the variation of the OH radical density in the gas phase. No increase in the surface tension was observed in the solution containing a trapping agent for liquid-phase OH radicals. These experimental results suggest that OH radicals act to increase the surface tension. However, the behavior of the surface tension cannot be explained perfectly by considering only the action of OH radicals.


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