• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.204-207
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• 2011

A particle counting system that can also provide sensitive, specific chemical information, while consuming very less power, occupying less space, and being inexpensive has been developed. This system uses a microwave plasma torch (MPT) as the excitation source for atomic emission spectrometry (AES). Emission from a single particle can be detected, and the wavelength at which the emission is observed indicates the elements present in the particle. It is believed that correlating the particle size and emission intensity will allow us to estimate the particle size in addition to abovementioned capabilities of the system. In the long term, this system can be made field-portable, so that it can be used in atmospheric aerosol monitoring applications, which require real-time detection and characterization of particles at low concentrations.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2004.11a
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• pp.195-200
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• 2004

Carbon dioxide ($CO_2$) and methane (CH$_4$) are two major greenhouse Bases. $CO_2$is a stack gas of many industrial processes and the main product of the hydrocarbon combustion. There is recent research interest on the synthesis gas (syngas) formation from $CO_2$ and CH$_4$, via the following reaction: CH$_4$+$CO_2$longrightarrow 2H$_2$+$CO_2$, in order to reduce the greenhouse effects and to synthesize various chemicals, Preliminary experiments were conducted on the conversion of $CO_2$ and CH$_4$ to syngas by making use of a microwave plasma torch at atmospheric pressure. Conversion rates of $CO_2$and CH$_4$ to hydrogen (H$_2$), carbon monoxide (CO) and higher hydrocarbons were investigated using Gas Chromatography (GC) and Fourier Transform Infrared (FTIR). The experimental data indicate that the main products were H$_2$, CO and small amount of higher hydrocarbons, such as ethylene (C$_2$H$_4$).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05a
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• pp.15-17
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• 2001

A new possibility of our atmospheric cold plasma torch has been examined on the surface treatment of an air-exposed vulcanized rubber compound. The plasma treatment effect was evaluated by the bondability with another rubber compound using a polyurethane adhesive.

• Transactions on Electrical and Electronic Materials
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• v.2 no.4
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• pp.7-10
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• 2001

A new possibility of our atmospheric cold plasma torch has been examined on the surface treatment of an air-exposed vulcanized rubber compound. The plasma treatment effect was evaluated by the bondability with another rubber compound using a polyurethane adhesive. The adhesion property was improved by the treatment with plasma containing oxygen radicals. The oxygen radical generation from the plasma was verified and its efficiency was found to be dependent on the cathode material.

• Elastomers and Composites
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• v.39 no.1
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• pp.3-11
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• 2004

Plasma treatment is frequently used to increase surface functionality and surface activity. It enables to improve various surface properties such as catalytic selectivity, printability, and interfacial adhesion between various materials. Surface or the ethylene-vinyl acetate (EVA) is exposed under an atmospheric pressure plasma torch (APPT), generated by dielectric barrier discharge (DBD), and the treated surfaces are systemically investigated. Argon, air, and oxygen are used as a processing gas. Properties of the treated EVA surfaces are investigated by the zeta-potential measurements and surface free energies. It is shown that the plasma treatment leads to a drastic increase of surface functional groups of EVA, as the increase of its adhesion energy ($G_{IC}$). Therefore, it is concluded that the APPT process is an effective means to improve adhesion of EVA and polyurethane (PU).

• Journal of the Korean Vacuum Society
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• v.15 no.2
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• pp.117-138
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• 2006

Plasmas can be made by electrical discharge on earth. Most of the plasmas on earth have been generated in low pressure environments where the pressure is less than one millionth of the atmospheric pressure. However, there are many plasma applications which require high pressure plasmas. Therefore, scientists start research on plasma generation at high pressure to avoid use of expensive vacuum equipments. Large-volume inexpensive plasmas are needed in the areas of material processing, environmental protection and improvement, efficient energy source and applications, etc. We therefore developed new methods of plasma generations at high pressure and carried out research of applying these plasmas to high tech industries representing 21 century. These research fields will play pivotal roles in material, environmental and energy science and technology in future.

• Journal of the Korean Ceramic Society
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• v.47 no.6
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• pp.618-622
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• 2010

Cost-effective purification methods of silicon were carried out in order to replace the conventional Siemens method for solar grade silicon. Firstly, acid leaching which is a hydrometallurgical process was preceded with grinded silicon powders of metallurgical grade (~99% purity) to remove metallic impurities. Then, plasma treatments were performed with the leached silicon powders of 99.94% purity by argon plasma at 30 kW power under atmospheric pressure. Plasma treatment was specifically efficient for removing Zr, Y, and P but not for Al and B. Another purification step by EB treatment was also studied for the 99.92% silicon lump which resulted in the fast removal of boron and aluminum. That means the two methods are effective alternative tools for removing the doping elements like boron and phosphor.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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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.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.293.1-293.1
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• 2013

탄소나노튜브(carbon nanotubes; CNTs)는 우수한 물성으로 인하여 전자소자, 에너지 저장매체, 투명전도막, 복합재료 등 매우 다양한 분야에 응용이 가능할 것으로 예측되고 있으며, 더욱이 이러한 특성은 구조변형, 화학적 도핑뿐만 아니라 표면처리를 통해서 제어가 가능하다고 알려져 있다. 이를 위해 기존에는 열처리를 통하여 CNTs를 표면처리한 결과들이 보고되었으나, 고온에서 장시간의 공정이 요구되는 열처리 공정의 단점을 보완하기 위하여 플라즈마 처리를 통해 상온에서 단시간의 공정으로 CNTs를 표면처리하는 방법이 제시되었다. 특히 최근에는, 향후 산업적 응용을 목적으로 종래의 진공 환경에서 벗어나 대기압 연속공정 개발을 위한 대기압 플라즈마 기반의 표면처리 공정에 대하여 관심이 집중되고 있는 상황이다. 본 연구에서는 대기압에서 플라즈마를 안정적으로 방전 및 유지 할 수 있는 플라즈마 토치 시스템을 구축하였고, 이를 이용하여 수직배향 CNTs를 표면 처리함으로써 그 영향을 살펴보았다. CNTs는 $SiO_2$ 웨이퍼 위에 증착한 철 촉매를 이용하여 $750^{\circ}C$에서 수직배향 합성하였으며, 원료가스로는 아세틸렌을 사용하였다. 대기압 플라즈마 장치의 경우 고전압 교류 전원장치를 이용하여 토치타입으로 제작하였다. 플라즈마는 아르곤과 질소가스를 시용하여 방전하고, 기판과의 거리 및 처리시간을 변수로 CNTs를 표면처리하였다. 플라즈마 처리 전후 접촉각 측정을 통하여 소수성이었던 CNTs 표면이 친수성으로 변화하는 것을 확인하였다. 또한 Raman 분석을 통하여 대기압 플라즈마의 처리조건에 따른 CNTs 의 구조적 결함 발생 정도를 정량화 시킬 수 있었다. 이를 통하여 대기압 플라즈마를 이용할 경우, CNTs의 구조적 손상을 최소화 하면서 효율적으로 표면특성을 변화시킬 수 있는 처리조건을 도출하였다.