• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1462-1463
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• 2008

패키징 재료로 유연성이 뛰어난 polydimethyl-siloxane (PDMS)를 사용하면 다양한 flexible packaging에 응용할 수 있다. 본 논문에서는 $O_2$ plasma를 이용한 PDMS의 표면 처리를 통해 PDMS의 표면에너지를 증가시키고, silicon과 PDMS 사이의 접착력 향상을 확인하였다. $O_2$ plasma power와 처리 시간에 따른 PDMS 표면의 접촉각을 측정하고 표면에너지를 산출하였는데, PDMS의 표면에너지는 $O_2$ plasma power에는 크게 영향을 받지 않고, plasma 처리 시간에 민감한 것으로 나타났다. Silicon-PDMS의 접착력 역시 plasma power에는 거의 영향을 받지 않았지만 plasma 처리 시간이 길어질수록 접착력이 커지는 것으로 확인되었는데 50W의 power로 25초 동안 처리한 조건에서 최대 130kPa의 압력까지 견디는 것으로 확인되었다. 이는 $O_2$ plasma 처리 시간이 길어짐에 따라 PDMS의 표면에너지가 커지고 이것이 silicon-PDMS의 접착력을 증가시키는 것을 나타낸다.

• Polymer(Korea)
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• v.24 no.1
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• pp.23-28
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• 2000

Autoadhesion strength of PS/PS Interfaces in solvent welding was determined as a function of processing conditions by butt joint test. It was verified that the chain mobility and surface roughness at PS/PS interface were enhanced by the applied solvent having a similar solubility parameter as PS and resulted in the dramatic improvement of autoadhesion strength at PS/PS interface. It was found that the mechanism of solvent welding is dependent upon the chain mobility due to the diffusion of solvent to PS interface and the contact area at interface. When the welding temperature is lower than the boiling point of applied solvent, the effect of chain mobility on autoadhesion strength was dominated, while contact area took more important role when welding temperature is above the boiling point of solvent. Autoadhesion strength increased with increasing contact time and contact temperature but :he effect of solvent on autoadhesion strength became smaller.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.123-126
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• 2003

The electrophoretic deposition method using the suspension solution with additives under the electric potential was applied for the fabrication of YBCO superconductor wire. This method was able to simplify the fabrication facilities, and produce an uniform and dense thick film. To improve the critical current density of deposited films, the additive PEGs(Poly Ethylene Glycole) with the molecular weight of 600, 1000 and 3400, were used as chemical binders for the suspension solution. The organic additive PEG showed better effects to the properties of YBCO superconductor wire. The PEG improved the adhesion between superconductor particles and suppressed the crack on the surface, which enhanced the surface uniformity and density of YBCO deposited film. It was found that acetone suspension solution showed better deposition properties than the others. The samples fabricated in the solution with the additive, 8 vol.% of 1% PEG(1000), showed the highest critical current density measured as $2300{\sim}2400\;Acm^2$ at 77 K, 0 T.

• Journal of Biosystems Engineering
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• v.22 no.4
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• pp.391-400
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• 1997

Using the soil bin systems, this study was carried out to investigate the tilling load characteristic for the three kinds of Japanese rotary blade and the possibility of common use for power tiller and tractor rotary. The results obtained from the study are summarized as follows : 1. At all tested soils. the average and maximum tilling torque of all tested blades increased as the tillage pitch did. 2. The torque requirements of newly designed and produced blade was less than that of blade which has been used on power tiller and tractor rotary. 3. The maximum tilling torque of new ONE were decreased 7%, 10~11％, 27% in comparing with another blades at clay loam, loam and sandy loam, respectively. 4. According to observation of the extent of soil adhesion on blade and the contact aspect of blade, new ONE is the most excellent of all tested rotary blades and till smoothly not to compress the untilled soil. From the results of this study. the newly developed blade(new ONE) proved to be good tilling load performance and had a conclusion that it is possible to use it on power tiller and tractor rotary in common.

• Journal of Fashion Business
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• v.8 no.5
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• pp.125-135
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• 2004

Hair coloring before the 1980s was mostly to hide white hair by dying in black. With the introduction of color TV, however, the size of the coloring market has been expanding. Nowadays, artificial synthetic dyes are widely used, which, though advantageous in many points, have problems such as harmful effects on the human body, carcinogenesis, environmental contamination and damage on hair. On the contrary, natural vegetables obtained from Curcuma Longa L., A. catechu, polygonum indigo, henna, etc. are little harmful to hair or the skin of the head and cause few environmental problems. In addition, as they are natural materials collected from nature, they are considered positively by consumers. Thus the present study started from the necessity of research on the convenient use of environment?friendly and side-effect-free natural dyes, coloring technology for reproducing original color, the improvement of adhesion rate, etc. From the present research were obtained yellow color from Curcuma Longa L., brown from A. catechu, blue from polygonum indigo and orange from henna. It is expected that, based on materials from previous researches, there may be more researches on the use of natural dyes as hair colors.

• Korean Journal of Materials Research
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• v.13 no.2
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• pp.120-125
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• 2003

A low melting borosilicate glass frit was used as an adhesion promoter, which enables $MnWO_4$to be sintered with in a reasonable sintering temperature range ($800∼1000^{\circ}C$). The glass was evaluated for glass transition temperature ($Τ_{g}$ X) and thermal expansion coefficient($\alpha$). Mechanical property (Vickers hardness), grain growth, the comparison of lattice parameter and pore distribution of sintered $MnWO_4$ with the frit were methodically discussed. As sintering temperature increased, a typical liquid phase sintering showed the rapid grain growth and high densification of X$MnWO_4$grain, improvement of hardness (until $920^{\circ}C$) and different pore size distribution. Resistance of sintered $MnWO_4$varied from 450k$\Omega$ to 8.8M$\Omega$ under the measuring humidify ranging from 30 to 90%. Thus, the results will contribute to the application of glass frit containing sensor materials and their future use.

• Transactions on Electrical and Electronic Materials
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• v.13 no.6
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• pp.267-272
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• 2012

Considering the properties of the carbon nano tubes (CNT), their inclusion into the polymer matrix vastly increases the properties of the resultant composite. However, this is not the case due to the poor interfacial adhesion of the CNT and the polymer matrix. The present approach focuses on increasing the interaction between the polymer matrix and the CNT through the chemical modification of the CNT resulting in allyl ester functionalized carbon nanotubes (ACNT) and silane functionalized carbon nano tubes (SCNT) which are capable of reacting with the polymer matrix during the curing reaction. The addition of ACNT/SCNT into unsaturated polyester resin (UPR) resulted in the improvement of the electrical properties of resulted nanocomposites in comparison to the CNT. The surface resistivity, volume resistivity, dielectric strength, dry arc resistivity, and the comparative tracking index of the nanocomposites were significantly improved in comparison to CNT. The chemical modification of CNT was confirmed via spectroscopy.

• Journal of the Korean institute of surface engineering
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• v.49 no.6
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• pp.567-574
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• 2016

We have analyzed chemical properties of polysiloxane and polysilazane films, respectively, as sealing materials for electrostatic chuck (ESC) and have investigated the possibility of polysilazane as an alternative sealant to polysiloxane. It has been revealed that Si-O with organic bonding ($Si-CH_3$) existed in polysiloxane films compared to only pure Si-O bonding in polysilazane films. The sealing property of polysilazane has been found outstanding even in a short time of application. In the polysiloxane films containing $H_2O$, pin holes have been found possibly due to $CO_2$ gas evolution, and low adhesion with Si substrate has been observed after heat stress test in connection with the existence of organic bonding. After acid resistance test in 0.5 vol.% HF, 68 wt.% $HNO_3$, and 37 wt.% HCl solution, polyilazane films have shown a longer survival times. Compared to the conventional polysiloxane sealant, polysilazane is expected as a new sealing material because of good thermal and chemical stability.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.12
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• pp.1027-1033
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• 2007

In this research, the polishing pad for W CMP has been analyzed to understand stabilization of polishing performance. For stabilization of process, the polishing pad condition is one of important factors. The polishing pad plays a key role in polishing process, because it contact with reacted surface of wafer[1]. The physical property of pad surface is ruled by conditioning tool which makes roughness and profile of pad surface. Pad surface affects on polishing performance such as RR(Removal Rate) and uniformity in CMP. The stabilized pad surface has stable roughness. And its surface has high level of wettability which can increase the probability of abrasive adhesion on pad. The result of this research is that the reduction of break-in and dummy polishing process were achieved by artificial machining to make stable pad surface. In this research, urethane polishing pad which is named IC pad(Nitta-Haas Inc.) and has micro pore structure, is studied. Because, this type of pad is the most conventional type.

• Korean Journal of Materials Research
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• v.12 no.1
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• pp.10-15
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• 2002

Melt blends of maleic anhydride grafted polypropylerle(PP-g-MA) and Nylon 6 were prepared to study the influence of chemical reaction between the two polymer components. By adding the MA grafted polystyrene pold (ethylene/butadiene) and polystyrene[SEBS-g-MA] as the compatible modifiers to reinforce the impact resistance, the Izod impact strength, high rate impact strength and morphology were studied. The notched Izod impact strength increased with the content of PP-g-MA and SEBS- g-MA. The energy of high rate impact strength increased as the thickness of specimen increased, while, it increased as the specimen displacement decreased. In the morphology observed by SEM, finally, we confirmed the improvement of the compatibilization and interfacial adhesion with the content of SEBS-g-MA. The continuous phase of PP-g-MA was the main cause of the modified properties.