• Applied Chemistry for Engineering
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• 제22권3호
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• pp.261-265
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• 2011

The sterilization effects of atmospheric pressure plasma with the mixture of argon and oxygen were analyzed. The plasma reactor with the shape of dielectric barrier discharge produced the uniform distribution of glow discharge and generated ozone gas effectively according to the various process parameters. The sterilization for E. coli was affected by power, oxygen ratio in the mixture gas, treatment time and distance between reactor and sample. The concentration of ozone was a major source for the sterilization of E. coli, which was enhanced by the increase of power and oxygen ratio. In this study, the effect of atmospheric pressure plasma treatment for the sterilization was confirmed and its result can deliver the atmospheric pressure plasma treatment as the novel sterilization method instead of conventional methods.

• Biomolecules & Therapeutics
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• 제22권6호
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• pp.477-490
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• 2014

Non-thermal atmospheric-pressure plasma, also named cold plasma, is defined as a partly ionized gas. Therefore, it cannot be equated with plasma from blood; it is not biological in nature. Non-thermal atmospheric-pressure plasma is a new innovative approach in medicine not only for the treatment of wounds, but with a wide-range of other applications, as e.g. topical treatment of other skin diseases with microbial involvement or treatment of cancer diseases. This review emphasizes plasma effects on wound healing. Non-thermal atmospheric-pressure plasma can support wound healing by its antiseptic effects, by stimulation of proliferation and migration of wound relating skin cells, by activation or inhibition of integrin receptors on the cell surface or by its pro-angiogenic effect. We summarize the effects of plasma on eukaryotic cells, especially on keratinocytes in terms of viability, proliferation, DNA, adhesion molecules and angiogenesis together with the role of reactive oxygen species and other components of plasma. The outcome of first clinical trials regarding wound healing is pointed out.

• Korean Chemical Engineering Research
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• 제49권6호
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• pp.835-839
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• 2011

The characteristics of torch-type atmospheric pressure plasma and its sterilization effects have been analyzed. The length of plasma flame was varied with the level of applied voltage and the mixture gases composed of argon and oxygen. The effect of plasma flame on the temperature increase of surface treated was limited to $43^{\circ}C$ as a maximum temperature under exposing time of 10 min. The sterilization for E. coli was strongly affected by the applied voltage, the oxygen ratio in the mixture gas and the treatment time. At a high concentration of ozone, the increase of treatment time under the direct contact with plasma flame yields to maximize the effect of the sterilization on E. coli.

• Journal of Environmental Science International
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• 제22권12호
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• pp.1561-1569
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• 2013

This study carried out a laboratory scale plasma reactor about the characteristics of chemically oxidative species (${\cdot}OH$, $H_2O_2$ and $O_3$) produced in dielectric barrier discharge plasma. It was studied the influence of various parameters such as gas type, $1^{st}$ voltage, oxygen flow rate, electric conductivity and pH of solution for the generation of the oxidant. $H_2O_2$ and $O_3$.) $H_2O_2$ and $O_3$ was measured by direct assay using absorption spectrophotometry. OH radical was measured indirectly by measuring the degradation of the RNO (N-Dimethyl-4-nitrosoaniline, indicator of the generation of OH radical). The experimental results showed that the effect of influent gases on RNO degradation was ranked in the following order: oxygen > air >> argon. The optimum $1^{st}$ voltage for RNO degradation were 90 V. As the increased of $1^{st}$ voltage, generated $H_2O_2$ and $O_3$ concentration were increased. The intensity of the UV light emitted from oxygen-plasma discharge was lower than that of the sun light. The generated hydrogen peroxide concentration and ozone concentration was not high. Therefore it is suggested that the main mechanism of oxidation of the oxygen-plasma process is OH radical. The conductivity of the solution did not affected the generation of oxidative species. The higher pH, the lower $H_2O_2$ and $O_3$ generation were observed. However, RNO degradation was not varied with the change of the solution pH.

• Journal of Adhesion and Interface
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• 제23권4호
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• pp.122-129
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• 2022

In this study, the hydrophilicity of the metal fiber is improved by introducing an oxygen-containing functional group to the fiber surface after treatment of the metal fiber using the oxygen plasma treatment time as an experimental variable. For the surface modification of metal fibers, changes in surface properties before and after plasma treatment were observed using SEM and x-ray photoelectron spectroscopy (XPS). In order to observe the effect of the plasma treatment time on the surface of the metal fiber, the change in contact angle of the metal fiber with respect to a polar solvent and a non-polar solvent was measured. After calculating the change in surface free energy using the measured contact angle, the contact angle and the surface free energy for metal fibers before and after oxygen plasma treatment were compared, and the correlation with the adhesion work was also considered. The microdroplet specimens were prepared to investigate the effect of surface changes of these metal fibers on the improvement of shear strength at the interface when combined with other materials and the interfacial shear strength was measured, and the correlation with the adhesion work was also identified. Therefore, the oxygen plasma treatment of the metal fiber results in an increase in the physical surface area on the fiber surface and a change in contact angle and surface energy according to the introduction of the oxygen-containing functional group on the surface. This surface hydrophilization resulted in improving the interfacial shear strength with the polymer resin.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.195-198
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• 2014

$Fuel/N_2$ and fuel/air mixtures were treated with non-thermal DBD plasma and the changes in characteristics of laminar diffusion flame have been observed. Flame of $Fuel/N_2$ mixture generated more soot under plasma condition while less amount of soot was formed from fuel/air mixture flame. Luminescence spectrum and gas chromatography results confirmed that plasma energy converts a fraction of fuel molecules into radicals, which then form $C_2$, $C_3$, $C_4$ and higher hydrocarbon under no oxygen condition or turn into CO, $CO_2$ and $H_2O$ when oxygen is present.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제18권5호
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• pp.450-456
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• 2005

In this paper, the effect of adhesion properties of semiconductive-insulating interface layer of silicone rubber on electrical properties was investigated. The modifications produced on the silicone surface by oxygen plasma were accessed using ATR-FTIR, contact angle and Surface Roughness Tester. Adhesion was obtained from T-peel tests of semiconductive layer haying different treatment durations. In addition, ac breakdown test was carried out for elucidating the change of electrical property with duration of plasma treatment. From the results, the treatment in the oxygen plasma produced a noticeable increase in surface energy, which can be mainly ascribed to the creation of O-H and C=O. It is observed that adhesion performance was determined by surface energy and roughness level of silicone surface. It is found that at dielectric strength was increased with improving the adhesion between the semiconductive and insulating interface.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 한국표면공학회 2013년도 춘계학술대회 논문집
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• pp.170-170
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• 2013

We present a novel etching technique for 2-dimentional (2-D) hexagonal boron nitride (h-BN) by using capacitively coupled plasma (CCP) of oxygen combined with a post-treatment by de-ionized (DI) water. Oxygen CCP etching process for h-BN has been systematically studied. It is found that a passivation layer was generated to obstruct further etching while it can be easily and radically removed by DI water. An essential cleaning effect also has been observed in the etching process, organic residues are successfully removed and the surface roughness has much decreased. Considering h-BN is the most important 2-D dielectric material and its potential application for graphene to silicon-based electronic devices, such an etching method can be widely used to control the 2-D h-BN thickness and improve the surface quality.

• Journal of the Korean institute of surface engineering
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• 제29권6호
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• pp.773-780
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• 1996

Silicon oxide films were prepared by using five kinds of organosilicon compound as gas sources without oxygen by rf plasma-enhanced CVD (PECVD). UV light was irradiated on a substrate vertically during deposition to enhance film oxidation and ablation of carbon contamination in a deposited films. Films prepared with UV irradiation contained less carbon than those prepared without UV irradiation. The oxidation of the films was improved by UN irradiation. The effect of UV irradiation was, however, not observed when the films were prepared with tetramethy lsilane (TMS) which contained no oxygen atom. Dissociated oxygen atoms from an organosilicon compound were excited in the plasma with UV irradiation around the substrate surface and affected the enhancement of film oxidation and ablation of carbon in the films.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제25권10호
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• pp.116-124
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• 2011

In this work, the effect of the initial concentration of methanol and ethanol, and the addition of oxygen molecules were discussed to improve the hydrogen generation using non-thermal plasma reactor effectively. In addition, the effect of ozone decomposition catalyst of manganese dioxide and its quantity was investigated. First, hydrogen concentration increased until an initial concentration of about 40,000[ppm] of methanol and thereafter it was saturated. Henceforth, hydrogen concentration decreased with increasing the oxygen percent on the carrier gas of nitrogen about both substances. Related with the effect of catalyst, it increased upto 60[g], but it was not changed largely after that. Consequently, it is confirmed that the hybrid process using plasma process and catalytic surface chemical reaction is a very promising way to increase the efficiency of hydrogen generation as investigated in this work.