• Title/Summary/Keyword: Microwave plasma treatment

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Surface Modification with Atmospheric Microwave Agron Plasma Jet Assisted with Admixture of H2O2 and Analysis of Plasma Characteristics

  • Won, I.H.;Shin, H.K.;Kwon, H.C.;Kim, H.Y.;Kang, S.K.;Lee, J.K.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.544-545
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    • 2013
  • Recently, low-temperature atmospheric-pressure plasmas have been investigated [1,2] for biomedical applications and surface treatments. Experiments for improving hydrophilicity of stainless steel (SUS 304) plate with atmospheric microwave argon and H2O2 mixture plasma jet [3] were carried out and experimental measurements and plasma simulations were conducted for investigating the characteristics of plasma for the process. After 30 s of low power (under 10 W) and low temperature (under $50^{\circ}C$) plasma treatment, the water contact angle decreased rapidly to around $10^{\circ}$ from $75^{\circ}$ and was maintained under $30^{\circ}$ for a day (24 hours). The surface free energy, calculated from the contact angles, increased. The chemical properties of the surface were examined by X-ray Photoelectron Spectroscopy (XPS) and the surface morphology and roughness were examined by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) respectively. The characteristics of plasma sources with several frequencies were investigated by Optical Emission Spectroscopy (OES) measurement and one-dimensional Particle-in-Cell (PIC) simulation and zero-dimensional global simulation [4]. The relation between plasma components and the efficacy of the surface modification were discussed.

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Therapeutic Effect of Low-Energy Nitrogen Plasma Pulses on Tinea Pedis

  • Kim, Heesu;Kim, Hyun-Jo;Cho, Sung Bin
    • Medical Lasers
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    • v.8 no.1
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    • pp.28-31
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    • 2019
  • Superficial fungal infections with dermatophytes, nondermatophyte molds, or yeasts are treated primarily with topical and/or systemic antifungal agents. Additional or alternative treatment modalities, particularly energy-delivering modalities, however, are used widely to induce fungicidal effects via selective photothermal reactions. In addition to light- or laser-based devices, plasma therapy also has antifungal properties. This report describes a Korean male patient with mycologically confirmed tinea pedis that was treated effectively with two sessions of nitrogen plasma treatment at one-week intervals using a plasma delivering system. Nitrogen plasma was prepared by loading a 0.28-ml inert nitrogen gas/pulse that was activated by a microwave generator. The other treatment settings were a nozzle diameter of 5 mm, pulse energy of 0.75 J, pulse duration of 7 msec, and two passes. One week after the first session of nitrogen plasma treatment, the patient exhibited marked reductions in scale and inflammation. One month after the final treatment, no clinical features of recurrence were found, and successive potassium hydroxide testing revealed negative results.

Non-thermal plasma technology for abatement of pollutant emission from marine diesel engine

  • Panomsuwan, Gasidit;Rujiravanit, Ratana;Ueno, Tomonaga;Saito, Nagahiro
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.10
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    • pp.929-934
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    • 2016
  • Plasma technology has long been regarded as a key essential tool in many industrial and technological sectors. However, the advancement of plasma technology in marine applications has not been fully realized yet. Herein, we present a short overview on the recent trends in utilization of plasma technology for air-pollution treatment in marine diesel exhaust. Four non-thermal plasma system, including electron beam dry scrubber (EBDS), dielectric barrier discharge (DBD), electron beam-microwave (EB-MW) plasma hybrid system, and plasma-catalytic hybrid system, are described with emphasis on their efficiency in removals of $NO_x$ and $SO_x$ gases. Non-thermal plasma has the great potential to be an efficient and environmentally compatible technique in simultaneous removals of $NO_x$ and $SO_x$ gases from the exhaust of marine diesel engine in the future.

EFFECT OF SUBSTRATE BIAS ON THE DIAMOND GROWTH USING MICROWAVE PLASMA CVD

  • Sakamoto, Yukihiro;Takaya, Matsufumi
    • Journal of the Korean institute of surface engineering
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    • v.32 no.3
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    • pp.303-306
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    • 1999
  • On the effect of substrate bias at first stage of diamond synthesis at lower substrate temperature(approximately 673K) using microwave plasma CVD and effect of reaction gas system for the bias enhanced nucleation were studied. The reaction gas was mixture of methane and hydrogen or carbon monoxide and hydrogen. The nucleation density of applied bias -150V using $CH_4-H_2$ reaction gas system, significantly higher than that of $C-H_2$ reaction gas system. When the $CH_4-H_2$ reaction was used, nucleation density was increased because of existence of SiC as a interface for diamond nucleation. By use of this negative bias effect for fabrication of CVD diamond film using two-step diamond growth without pre-treatment, fabrication of the diamond film consist of diamond grains $0.2\mu\textrm{m}$ in diameter was demonstrated

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Application of cold atmospheric microwave plasma as an adjunct therapy for wound healing in dogs and cats

  • Jisu Yoo;Yeong-Hun Kang;Seung Joon Baek;Cheol-Yong Hwang
    • Journal of Veterinary Science
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    • v.24 no.4
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    • pp.56.1-56.13
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    • 2023
  • Background: Cold atmospheric plasma is a novel innovative approach for wound care, and it is currently underrepresented in veterinary medicine. Objectives: To investigate the efficacy and safety of using cold atmospheric microwave plasma (CAMP) as an adjunct therapy for wound healing in dogs and cats. Methods: Wound healing outcomes were retrospectively analyzed using clinical records of client-owned dogs and cats who were first managed through standard wound care alone (pre-CAMP period) and subsequently via CAMP therapy (CAMP period). The degree of wound healing was estimated based on wound size and a modified wound scoring system. Results: Of the 27 acute and chronic wounds included in the analysis, 81.48% showed complete healing after the administration of CAMP as an adjunct therapy to standard care. Most wounds achieved complete healing in < 5 weeks. Compared with the pre-CAMP period, the rate of wound healing significantly increased every week in the CAMP period in terms of in wound size (first week, p < 0.001; second week, p = 0.012; third week, p < 0.001) and wound score (first week, p < 0.001; second week, p < 0.001; third week, p = 0.001). No adverse events were noted except for mild discomfort and transient erythema. Conclusions: CAMP is a well-tolerated therapeutic option with immense potential to support the treatment of wounds of diverse etiology in small animal practice. Further research is warranted to establish specific criteria for CAMP treatment according to wound characteristics.

Recent Study of Thermal Spray for Green Automotive Industry (친환경 자동차산업의 용사(Thermal spray)에 대한 최신 연구동향)

  • Yoo, Ho-Cheon
    • Journal of Welding and Joining
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    • v.32 no.3
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    • pp.43-52
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    • 2014
  • Recent developing tendency of thermal spray for green automotive industry are studied by searching of NDSL, KIPRIS, ScienceDirect and so on. Spraying techniques such as plasma spray, microwave treatment, dry-ice blasting, HVOF thermal spray, cold spraying, aerosol deposition are introduced, further more spraying materials such as nano particles, intermetallic compound, TiAlN, TiC, Si-Al alloys are investigated.

Effect of DC Bias on the Growth of Nanocrystalline Diamond Films by Microwave Plasma CVD (마이크로웨이브 플라즈마 CVD에 의한 나노결정질 다이아몬드 박막 성장 시 DC 바이어스 효과)

  • Kim, In-Sup;Kang, Chan Hyoung
    • Journal of the Korean institute of surface engineering
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    • v.46 no.1
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    • pp.29-35
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    • 2013
  • The effect of DC bias on the growth of nanocrystalline diamond films on silicon substrate by microwave plasma chemical vapor deposition has been studied varying the substrate temperature (400, 500, 600, and $700^{\circ}C$), deposition time (0.5, 1, and 2h), and bias voltage (-50, -100, -150, and -200 V) at the microwave power of 1.2 kW, working pressure of 110 torr, and gas ratio of Ar/1%$CH_4$. In the case of low negative bias voltages (-50 and -100 V), the diamond particles were observed to grow to thin film slower than the case without bias. Applying the moderate DC bias is believed to induce the bombardment of energetic carbon and argon ions on the substrate to result in etching the surfaces of growing diamond particles or film. In the case of higher negative voltages (-150 and -200 V), the growth rate of diamond film increased with the increasing DC bias. Applying the higher DC bias increased the number of nucleation sites, and, subsequently, enhanced the film growth rate. Under the -150 V bias, the height (h) of diamond films exhibited an $h=k{\sqrt{t}}$ relationship with deposition time (t), where the growth rate constant (k) showed an Arrhenius relationship with the activation energy of 7.19 kcal/mol. The rate determining step is believed to be the surface diffusion of activated carbon species, but the more subtle theoretical treatment is required for the more precise interpretation.

A Study on the Characterization of Ni-C Thin Films Utilizing a Dual-Source Deposition System (듀얼 소스 증착장치를 이용한 Ni-C 박막의 특성에 관한 연구)

  • Han, Chang-Suk;Chun, Chang-Hwan;Han, Seung-Oh
    • Journal of the Korean Society for Heat Treatment
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    • v.21 no.5
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    • pp.235-243
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    • 2008
  • Ni-C composite films were prepared using a combination of microwave plasma CVD and ion beam sputtering deposition working in a codeposition way. The structure of these films was characterized by energy-dispersive X-ray diffraction (EDXRD), transmission electron microscopy (TEM) and Raman spectroscopy. It was found that a nickel carbide phase, $Ni_3C$ (hcp), formed as very fine crystallites over a wide temperature range when Ni-C films were deposited at low $CH_4$ flow rates. The thermal stability of this nonequilibrium carbide $Ni_3C$ was also studied. As a result, the $Ni_3C$ carbide was found to decompose into nickel and graphite at around $400^{\circ}C$. With high $CH_4$ flow rates (> 0.2 sccm), the structure of the Ni-C films became amorphous. The formation behavior of the carbide and amorphous Ni-C phases are discussed in relation to the electrical resistivity of the films.

Effect of Hydrogen Plasma Pre-treatment on Growth of Carbon Nanotubes by a Microwave PECVD Method (마이크로웨이브 플라즈마 화학기상증착장비를 사용하여 합성한 탄소나노튜브의 니켈 촉매층 수소 플라즈마 전처리조건에 따른 성장특성)

  • Choi, Won-Seok;Choi, Sung-Hun;Hong, Byung-You;Kim, Jung-Tae;Lim, Dong-Gun;Yang, Kea-Joon;Park, Young;Kim, Do-Young;Lee, Jae-Hyeoung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.189-190
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    • 2005
  • 본 논문에서는 탄소나노튜브를 성장시키기 전 과정인 전처리시 촉매 층에 인가되는 마이크로웨이브 파워에 따른 탄소나노튜브의 성장 및 특성 변화를 관찰하였다. 촉매층으로 사용되는 Ni층과 adhesion층으로 사용되는 Ti층은 마그네트론 스퍼터링 방식으로 증착하였고, 탄소나노튜브 성장에는 마이크로웨이브 플라즈마 화학기상 증착기를 사용하였다 탄소나노튜브의 성장특성은 평면과 단면 SEM image를 통하여 관찰하였으며, Raman spectrometer 분석을 통하여 성장된 탄소나노튜브의 구조적 특성을 알아보았다.

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Characteristics of Low Dielectric Constant SiOF Thin Films with Post Plasma Treatment Time (플라즈마 후처리 시간에 따른 저유전율 SiOF 박막의 특성)

  • 이석형;박종완
    • Journal of the Korean Vacuum Society
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    • v.7 no.3
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    • pp.167-272
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    • 1998
  • The fluorine doped silicon oxide (SiOF) intermetal dielectric (IMD) films havc been of interest due to their lower dielectric constant and compatibility with existing process tools. However, instability issues related to hond and increasing dielectric constant due to water absorption when the SiOF film was exposured to atmospheric ambient. Therefore, the purpose nf this research is to study the effect of post oxygen plasma treatment on the resistance of nioisture absorption and reliability of SiOF film. Improvement of moisture ahsorption resistance of SiOF film is due to the forming of thin $SiO_2$ layer at the SiOF film surface. It is thought that the main effect of the improvement of moisture absorption resistance was densification of the top layer and reduction in the numher of Si-F honds that tend to associate with OH honds. However, the dielectric constant was inucased when plasma treatment time is above 5 min. In this study, therefore, it is thought that the proper plasma treatment time is 3 min when plasma treatment condition is 700 W of microwave power, 3 mTorr of process pressure and $300^{\circ}C$ of substrate temperature.

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