• Textile Coloration and Finishing
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• v.27 no.1
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• pp.18-26
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• 2015

para-aramid fibers were treated by atmosphere air plasma to improve the interfacial adhesion. The wettability of plasma-treated aramid fiber was observed by means of dynamic contact angle surface free energy measurement. Surface roughness were investigated with the help of scanning electron microscopy and atomic force microscopy. The tensile test of aramid fiber roving was carried out to determine the effect of plasma surface treatments on the mechanical properties of the fibers. A pull-out force test was carried out to observe the interfacial adhesion effect with matrix material. It was found that surface modification and a chemical component ratio of the aramid fibers improved wettability and adhesion characterization. After oxygen plasma, it was indicated that modified the surface roughness of aramid fiber increased mechanical interlocking between the fiber surface and vinylester resin. Consequently the oxygen plasma treatment is able to improve fiber-matrix adhesion through excited functional group and etching effect on fiber surface.

• Journal of the Korean institute of surface engineering
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• v.53 no.6
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• pp.285-292
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• 2020

Ancient cultural heritage made up of wood and organic fibers have been easily disintegrated or decomposed by various microorganisms like bacteria and fungi. Here, we demonstrate the effectiveness of an atmospheric pressure plasma jet (APPJ) system to sterilize the microorganisms in tangible cultural heritage. We collected several specimens from the surface of ancient documents and wooden artifacts. Finally, two bacteria and two fungi were prepared and sterilized using the APPJ treatment. The APPJ system is beneficial to its simple apparatus, quick operation time, and cost-effectiveness. Bacteria were almost sterilized within only 1 min treatment using 15 % O2 and applied bias voltage of 100 V. In case of the fungi, sterilization rate reached over 83 % but difficult to reach over 90 % even 10 min treatment. According to the plasma diagnostics using optical emission spectroscopy, it was found that the reactive oxygen species such as OH groups are critical for sterilization of microorganisms. Although further efforts should be performed, we believe that efficient sterilization could be realized by the simple, quick, and portable APPJ treatment system.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.5
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• pp.319-325
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• 1999

Direct current(d.c.)leakage current voltage characteristics of radio-frequencymagnetron sputtered BaTa\sub 2\O\sub 6\ film capacitors with aluminum(A1) top and indium tin oxide (ITO) bottom electrodes have been investigatedas a function of applied field and temperature. In order to study surfacetreatment effect on the electrical characteristics of as-deposited film weperformed exposure of oxygen plasma on $BaTa_2O_6$ surface. d. c.current-voltage (I-V), bipolar pulse charge-voltage (Q-V), d. c. current-time (I-t) andcapacitance-frequency (C-f) analysis were performed on films. All ofthe films exhibita low leakage current, a high breakdown field strength (3MV/cm-4.5MV/cm), and high dielectric constant (20-30). From the temperature dependence of leakage current,we can conclude that the dominant conduction mechanism is ascribed toSchottky emission at high electric field (>1MV/cm) and hopping conduction at lowelectric field (<1MV/cm). According to our results, the oxide plasma surfacetreatmenton as-deposited $BaTa_2O_6$ resulted in lowering interfacebarrier height and thus, leakage current when a negative voltage applied to the A1 electrode. This can be explained by reduction of surface contamination via etching surface and filling defects such as oxygen vacancies.

• Fibers and Polymers
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• v.6 no.2
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• pp.169-173
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• 2005

Low temperature plasma (LTP) treatment was applied to wool fabric with the use of a non-polymerizing gas, namely oxygen. After the LTP treatment, the fabric properties including low-stress mechanical properties, air permeability and thermal properties, were evaluated. The low-stress mechanical properties were evaluated by means of Kawabata Evaluation System Fabric (KES-F) revealing that the tensile, shearing, bending, compression and surface properties were altered after the LTP treatment. The changes in these properties are believed to be related closely to the inter-fiber and inter-yam frictional force induced by the LTP. The decrease in the air permeability of the LTP-treated wool fabric was found to be probably due to the plasma action effect on increasing in the fabric thickness and a change in fabric surface morphology. The change in the thermal properties of the LTP-treated wool fabric was in good agreement with the above findings and can be attributed to the amount of air trapped between the yams and fibers. This study suggested that the LTP treatment can influence the final properties of the wool fabric.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.4
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• pp.632-637
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• 2003

In this study, the effect of surface treatment of CFRP and aluminum on the fracture toughness of CFRP/aluminum composites was investigated. CFRP was surface-treated by Ar$^{+}$ ion beam under oxygen environment, and the aluminum was surface-treated by DC plasma. CFRP was adhesively bonded to aluminum using the secondary bonding procedure. Cracked lap shear specimens were used to determine fracture toughness. Three cases of cracked lap shear specimens were made depending on the surface treatment. The values of fracture toughness of three cases were compared to each other It was found that the fracture toughness of ion beam-treated CFRP/aluminum composites was almost 72 % higher than that of unrented CFRP/aluminum composites. The fracture toughness of CFRP/plasma-treated aluminum composites was 50 % higher than that of untreated CFRP/aluminum composites.s.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.2
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• pp.147-150
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• 2019

There is a need for the development of transparent conductive materials that are economical and environmentally friendly with exhibit low resistivity and high transmittance in the visible spectrum. In this study, the deposition rate and uniformity of Al-doped ZnO-thin films were improved by changing the Z-motion of the sputtering system. The deposition rate and the uniformity were determined to be 3.44 nm/min and 1.23%, respectively, under the 10 mm Z-motion condition. During $O_2$ plasma treatment, the intrusion-type metal elements in the thin film were reduced, which contributed to an oxygen vacancy reduction in addition to structural stabilization. Moreover, the sheet resistance was more easily saturated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.147-148
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• 2005

In this work, recovery of semiconductive silicone rubber on oxygen plasma treatment was investigated in terms of X-ray photoelectron spectroscopy(XPS). The adhesion characteristics of semiconductive-insulating interface layer of silicone rubber were studied by measuring the T-peel strengths. As a result, surface methyl groups is removed and an oxidized layer containing Si atoms bound to 3 or 4 oxygens appears. The surface is later covered by a very thin layer due to migration of low-molecular-weight components from the bulk, resulting in decreasing the degree of adhesion of the semiconductive-insulating interface layer of silicone rubber these results are probably due to reorientation of polar groups or migration of low-molecular-weight.

• Fibers and Polymers
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• v.7 no.3
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• pp.262-269
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• 2006

In this paper, the effects of low temperature plasma (LTP) treatment on the dyeing properties of the wool fiber were studied. The wool fibers were treated with oxygen plasma and three types of dye that commonly used for wool dyeing, namely: (i) acid dye, (ii) chrome dye and (iii) reactive dye, were used in the dyeing process. For acid dyeing, the dyeing rate of the LTP-treated wool fiber was greatly increased but the final dyeing exhaustion equilibrium did not show any significant change. For chrome dyeing, the dyeing rate of the LTP-treated wool fiber was also increased but the final dyeing exhaustion equilibrium was only increased to a small extent. In addition, the rate of afterchroming process was similar to the chrome dyeing process. For the reactive dyeing, the dyeing rate of the LTP-treated wool fiber was greatly increased and also the final dyeing exhaustion equilibrium was increased significantly. As a result, it could conclude that the LTP treatment could improve the dyeing behavior of wool fiber in different dyeing systems.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.12
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• pp.1078-1084
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• 2006

Impurity contamination induced by $CF_4\;and\;HBr/Cl_2/O_2$ plasma etching on Si surface was examined by using surface spectroscopes. XPS(x-ray photoelectron spectroscopy) surface analysis showed that F of 0.4 at % exists in the surface layer in the form of Si-F bonding but Br and Cl are below the detection limit $(0.1{\sim}1.0%)$ of the spectroscope. Static-SIMS(secondary ion mass spectrometry) surface analysis showed that the etched Si surface was contaminated with etching gas elements such as H, F, Cl and Br, and they existed to the depth of about $20{\sim}40nm$. The etched Si surface was treated with three different methods that were HF dip, thermal oxidation followed by HF dip and oxygen-plasma oxidation followed by HF dip. They showed an effect in reducing the impurity contamination and the oxygen-plasma oxidation followed by HF dipping method appears to be a little bit more effective.

• Journal of Adhesion and Interface
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• v.8 no.3
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• pp.1-8
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• 2007

An atmospheric plasma pre-treatment method was applied to polyurethane foam to improve its contact angle and adhesion. In order to investigate the optimum reaction condition of plasma treatment, type of reaction gas (nitrogen, argon, oxygen, air), rate of gas flow (30~150 mL/min), and reaction time (0~30 sec) were examined in a plate plasma reactor. Also, the effects were compared to those of a conventional vacuum plasma pre-treatment system. The result of the surface modification with respect to the treatment procedure was characterized by using SEM and ATR-FTIR. Due to a decrease of the contact angle of polyurethane foam, the greatest adhesion strength was achieved at a flow rate of 100 mL/min and at a reaction time of 10s for N2 gas. Consequently, the atmospheric plasma treatment reduced the contact angle of the polyurethane foam and also resulted in the improvement of the peel strength.