Preliminary Study on Applications of an Atmospheric-Pressure Argon Plasma Discharge With a Single-Electrode Configuration

In this study, we conducted experiments to investigate the electrical and optical characteristics of a non-equilibrium Ar-N2 plasma discharge at atmospheric pressure. To obtain the plasma discharge we used our indigenously designed plasma generating device named CAPPLAT (Cold Atmospheric Pressure Plasma Torch) which was manufactured by Cresur Corporation. The plasma discharge obtained with only Ar gas was quite filamentary. So, to achieve a homogeneous discharge N2 gas was admixed. The effects of different volumes of admixed N2 gas were also studied. The optical emission spectroscopy was used to study the active charged species in the plasma discharges. The further increased volume of N2 gas further suppressed the emission intensity of Ar metastables but at the same time the emission intensity of the second positive system of nitrogen molecules (N2(C3Πu) enhanced significantly. It can be concluded that in Ar- plasma discharge, argon metastables are the main energy carriers but when N2 gas is added to the feeding gas (Ar) for plasma generation, the second positive system of nitrogen molecules (N2(C3Πu) become the main energy carriers. On the other hand the addition of the N2 gas doesn’t change the electrical characteristics of plasma discharge significantly. To identify the effectiveness of the CAPPLAT as a tool for sterilization, highly environmental stress resistant bacterial (Bacillus subtilis) endospores were treated for different durations. We could successfully deactivate the population of 1.0X107 to 4.0X107 Bacillus endospores/ml. The details of this experiment are discussed in our next paper.

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Surface modification of PMMA polymer and its composites with PC61BM fullerene derivative using an atmospheric pressure microwave argon plasma sheet

Scientific Reports ◽

10.1038/s41598-021-88553-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Andrzej Sikora ◽

Dariusz Czylkowski ◽

Bartosz Hrycak ◽

Magdalena Moczała-Dusanowska ◽

Marcin Łapiński ◽

...

Keyword(s):

Contact Angle ◽

Surface Modification ◽

Chemical Composition ◽

Water Contact Angle ◽

Plasma Sheet ◽

Atmospheric Pressure ◽

Argon Plasma ◽

Fullerene Derivative ◽

Water Contact ◽

Pmma Polymer

AbstractThis paper presents the results of experimental investigations of the plasma surface modification of a poly(methyl methacrylate) (PMMA) polymer and PMMA composites with a [6,6]-phenyl-C61-butyric acid methyl ester fullerene derivative (PC61BM). An atmospheric pressure microwave (2.45 GHz) argon plasma sheet was used. The experimental parameters were: an argon (Ar) flow rate (up to 20 NL/min), microwave power (up to 530 W), number of plasma scans (up to 3) and, the kind of treated material. In order to assess the plasma effect, the possible changes in the wettability, roughness, chemical composition, and mechanical properties of the plasma-treated samples’ surfaces were evaluated by water contact angle goniometry (WCA), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The best result concerning the water contact angle reduction was from 83° to 29.7° for the PMMA material. The ageing studies of the PMMA plasma-modified surface showed long term (100 h) improved wettability. As a result of plasma treating, changes in the samples surface roughness parameters were observed, however their dependence on the number of plasma scans is irregular. The ATR-FTIR spectra of the PMMA plasma-treated surfaces showed only slight changes in comparison with the spectra of an untreated sample. The more significant differences were demonstrated by XPS measurements indicating the surface chemical composition changes after plasma treatment and revealing the oxygen to carbon ratio increase from 0.1 to 0.4.

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