• Bulletin of the Korean Chemical Society
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• 제30권6호
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• pp.1357-1359
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• 2009

Many researchers studied cell culturing on surfaces with chemical functional groups. Previously, we reported surface properties of plasma polymerized ethylenediamine (PPEDA) films deposited by plasma enhanced chemical vapor deposition with various plasma conditions. Surface properties of PPEDA films can be controlled by plasma power during deposition. In this work, to analyze correlation of cell adherence/proliferation with surface property, we cultured rat intestinal epithelial cells-18 on the PPEDA films deposited with various plasma powers. It was shown that as plasma power was decreased, density of cells cultured on the PPEDA film surface was increased. Our findings indicate that plasma power changed the amine density of the PPEDA film surface, resulting in density change of cells cultured on the PPEDA film surface.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.784-785
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• 2010

전북대학교 고온플라즈마 응용연구센터 구축사업단에서는 MW급 초음속 플라즈마 풍동을 구축하고 있다. 구축되는 장비는 0.4MW/2.4MW급 Huels형 DC 플라즈마 장치 및 60kW/200kW급 RF 플라즈마 장치 등으로 구성되며 이러한 장비를 지원하는 공통지원설비가 별도로 구축되게 된다. 공통지원설비는 플라즈마 풍동을 구동하기 위한 수변전설비 및 가스공급설비, 냉각수공급설비, NOx 제거용 후처리 설비, 예비전원설비 등으로 구성되어 있다.

• 한국표면공학회지
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• 제36권1호
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• pp.9-13
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• 2003

Plasma polymerized organic thin films were deposited on Si(100), glass and metal substrates at $25∼100 ^{\circ}C$ using thiophene and toluene precursors by PECVD method. In order to compare physical and electrochemical properties of the as-grown thin films, the effects of the RF plasma power in the range of 30∼100 W and deposition temperature on both corrosion protection efficiency and physical properties were studied. We found that the corrosion protection efficiency ($P_{k}$), which is one of the important factors for corrosion protection in the interlayer dielectrics of microelectronic devices application, was increased with increasing RF power. The highest $P_{k}$ value of plasma polymerized toluene film (85.27% at 70 W) was higher than that of the plasma polymerized thiophene film (65.17% at 100 W), indicating inhibition of oxygen reduction. The densely packed and tightly interconnected toluene film could act as an efficient barrier layer to the diffusion of molecular oxygen. The result of contact angle measurement showed that the plasma polymerized toluene films have more hydrophobic surface than those of the plasma polymerized thiophene films.

• Current Photovoltaic Research
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• 제3권4호
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• pp.112-115
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• 2015

In this study, the surface of ITO films was modified using $N_2-O_2$ molecular plasma, and the effects of oxygen concentration in the plasma on the ITO surface properties were investigated. Upon plasma treatment of ITO films, the surface roughness of ITO films seldom changed up to the oxygen concentration in the range of 0% to 40%, while the roughness of the films slightly changed at or above the oxygen concentration of 60%. The contact angle of water droplet on ITO films dramatically changed with varying oxygen concentration in the plasma, and the minimum value was found to be at the oxygen concentration of 20%. The plasma resistance at this condition exhibited a maximum value, and the change of resistance showed an inverse relationship compared to that of contact angle. From these results, it was conjectured that the chemical reactions in the sheath of the molecular plasma dominated more than the physical actions due to energetic ion bombardment, and also the plasma resistance could be used as an indirect indicator to qualitatively diagnosis the state of plasma during the plasma treatment.

• 한국연소학회지
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• 제10권4호
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• pp.24-32
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• 2005

Various types of plasma source applied in $CH_4$ decomposition process are compared. DBD by pulse and AC power, spark by pulse and AC power, rotating arc and hollow cathode plasma are chosen to be compared. The results show that $CH_4$ conversion per given unit power is relatively high in hollow cathode plasma and rotating arc that induces rather high temperature condition and that is why both thermal dehydration and plasma induced decomposition contribute for the overall process. In case of DBD wherein high temperature electron and low temperature gas molecule coexist, the process shows low conversion rate, for in rather low temperature condition the contribution of thermal dehydration is lowered. Selectivity of $C_2H_6$ and $C_2H_2$ is shown to be a good parameter of the relative contribution of plasma chemistry in the overall process. From the results we concluded that required condition of plasma source for a cost effective and high yield $CH_4$ decomposition is to have characteristics of both thermal plasma and non thermal plasma in which temperature is high above a certain threshold state for thermal dehydration and electron induced collision is maximized in the same breath.

• 한국표면공학회지
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• 제38권3호
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• pp.118-125
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• 2005

Low temperature plasma treatment with different gases and rf powers were performed to improve the adhesion strength between polytetrafluoroethylene(PTFE) and electroless deposited copper. According to the research, $H_2$ plasma having hydrogen radical was more effective in surface polarity modification than $O_2$ plasma due to the defluorination reaction. However, surface roughness of PTFE was more increased with $O_2$ than $H_2$ plasma. PTFE treated with $120W-O_2$ plasma and $250w-H_2$ plasma, consecutively showed rougher surface than single step $250w-H_2$ plasma treated one and more hydrophilic than single step $120W-O_2$ plasma treated one. And it showed 5B tape test grade, which is better adhesion property than 1B or 3B obtained by single step plasma treatment. In addition, adhesion strength between PTFE and Cu deposit is also deeply affected by residual water on its interface.

• 반도체디스플레이기술학회지
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• 제17권2호
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• pp.16-19
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• 2018

The development speed of semiconductor and display device manufacturing technology is growing faster than the development speed of process equipment. So, there is a growing need for process diagnostic technology that can measure process conditions in real time and directly. In this study, a plasma diagnosis was carried out using impedance variation due to the plasma discharge. Variation of the measurement impedance appears as a voltage change at the reference impedance, and the plasma density is calculated using this. The above experiment was conducted by integrating the plasma diagnosis system and the linear atmospheric pressure DBD plasma source. It was confirmed that plasma density varies depending on various parameters (gas flow rate, $Ar/O_2$ mixture ratio, Input power).

• 공업화학
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• 제32권1호
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• pp.49-54
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• 2021

메틸 메타크릴레이트 분자를 전구체로 사용하여 원격 플라즈마 방식으로 중합체를 합성하는 반응에서 플라즈마 출력, 반응 압력 및 직접-간접 플라즈마 방식이 필름의 성장속도 및 화학결합 구조에 미치는 영향을 조사하였으며, FT-IR, XPS 등 분광학적 분석과 Langmvir 탐침을 사용한 플라즈마 특성 진단 결과와 함께 고찰하였다. 플라즈마 출력과 반응 압력이 증가하면 성장속도가 증가하지만 특정 영역을 넘어서면 식각 효과와 잦은 충돌로 인해 활성화 효율이 낮아져 다시 감소하였다. 중합 필름의 FT-IR과 XPS 분석 결과, 필름 내 탄소/산소 조성비는 플라즈마 출력이 커질수록 증가하였으며, 탄화수소성 C-C 탄소 조성비는 증가하는 반면 에스터성 COO 탄소 조성비는 감소하였다. 직접 플라즈마법이 간접 플라즈마법에 비해 필름의 성장속도는 2~5배 빠르지만, 전구체의 분자 구조를 유지하기 위해서는 간접 플라즈마법이 유리함을 확인하였다.

• 한국식품위생안전성학회:학술대회논문집
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• 한국식품위생안전성학회 2002년도 춘계학술발표대회 및 심포지움
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• pp.138-138
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• 2002

Oxidative stress has been associated with a number of diseases in human. Among the sources that can generate oxidative stress, it has been reported that iron can generate reactive oxygen species (ROS)with thiol. In iron overload state, increased thiol levels in plasma appeared to be associated with human mortality. In this study we examined whether iron could interact with thiols in plasma, generating ROS. In human plasma, unlike with Fe(III), Fe(II) increased lucigenin-enhanced chemiluminescence in concentration-dependent manner, and this was inhibited by SOD. Boiling of plasma did not affect chemiluminescence induced by Fe(II). Hovever, thiol depletion in plasma by pretreatment with N-ethylmaleimide (NEM)decreased Fe(II)-induced chemiluminescence significantly, suggesting that Fe(II) generated superoxide anion by the nonenzymatic reaction with plasma thiol. Consistent with this findings, albumin, the major thiol contributor in plasma, also generated ROS with Fe(II) and this generation was inhibited by pretreatment with NEM. Treatment with Fe(II) to plasma resulted un significant reduction of oxygen radical absorbance capacity (ORAC) value, suggest that total antioxidant capacity could diminished in iron overload state. In conclusion, In iron overload state, plasma may be affected by oxidative stress mediated by nonenzymatic reaction of Fe (II)with plasma thiol.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.179-179
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• 2016

A radio-frequency (RF) Inductively Coupled Plasma (ICP) torch system was used for boron-nitride nano-tube (BNNT) synthesis. Because of electrodeless plasma generation, no electrode pollution and effective heating transfer during nano-material synthesis can be realized. For stable plasma generation, argon and nitrogen gases were injected with 60 kW grid power in the difference pressure from 200 Torr to 630 Torr. Varying hydrogen gas flow rate from 0 to 20 slpm, the electrical and optical plasma properties were investigated. Through the spectroscopic analysis of atomic argon line, hydrogen line and nitrogen molecular band, we investigated the plasma electron excitation temperature, gas temperature and electron density. Based on the plasma characterization, we performed the synthesis of BNNT by inserting 0.5~1 um hexagonal-boron nitride (h-BN) powder into the plasma. We analysis the structure characterization of BNNT by SEM (Scanning Electron Microscopy) and TEM (Transmission Electron Microscopy), also grasp the ingredient of BNNT by EELS (Electron Energy Loss Spectroscopy) and Raman spectroscopy. We treated bundles of BNNT with the atmospheric pressure plasma, so that we grow the surface morphology in the water attachment of BNNT. We reduce the advancing contact angle to purity bundles of BNNT.