• 전자공학회논문지 IE
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• 제44권3호
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• pp.6-11
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• 2007

본 연구는 플라즈마 처리한 고분자 복합재료 표면의 접촉각, X-선광전자분광법(XPS) 및 코로나 대전에 의한 표면 정전특성을 분석하여 발생된 화학적 변화와 정전적 특성 변화를 고찰하여 열화 메커니즘을 도출하였다. 플라즈마 처리된 시료의 접촉각 및 표면전위는 표면에 카르복실기 라디칼을 포함하는 다량의 측쇄화가 집중적으로 발생되어 처리시간에 따라 급격한 친수화가 진행되었다. 플라즈마 처리로 인한 화학적 변화에서 표면에 carboxyl 라디칼이 주로 형성되면서 급격히 표면 친수화로 변화하였다. 정전변화를 분석한 전위감쇠 결과에서 미처리 시료는 부극성 표면을 나타내었으나, 친수화 표면은 carboxyl 라디칼(-COO*)을 포함하는 정극성 라디칼로 인해 정극성 표면으로 변화하여 부극성 전하가 빠르게 감소하였다.

• Macromolecular Research
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• 제11권4호
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• pp.283-290
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• 2003

Organic drugs including aspirin, omeprazole, and naproxen with three different levels of octanol/water partition coefficient were examined for their release behavior from the amphiphilic PCL-b-PEO-b-PCL (PCEC) matrix. Scanning electron micrograph (SEM) of PCEC illustrated a well defined two-phase morphology consisted of dispersed poly(ethylene oxide) (PEO) domain and continuous polycaprolactone (PCL) phase. Differential scanning calorimetry (DSC) and X-ray diffractometry (XRD) experiments veri tied that three model drugs are dissolved as a molecular dispersion in PCEC matrix. The release of hydrophilic aspirin closely followed the water absorption profile of the matrix indicating that its major fraction is present in PEO domain. However, substantial amount of aspirin present in less hydrophilic region displayed discontinuous biphasic release pattern. In the case of omeprazole with intermediate hydrophobicity consistent release behavior was observed for a period of 24 hrs after the rapid liberation of ca. 10% of the drug presumably partitioned in PEO phase. It was ascribed to the fact that the progressive hydration of PCEC matrix gradually increased the chance of drug/water exposure to compensate the exhaustion of device. Naproxen with the highest octanol/water distribution coefficient among three model drugs exhibited a limited release of 35% for 24 hrs. Finally, hydroxypropyl methylcellulose phthalate (HPMCP)/PCEC blend matrix demonstrated an accelerated and quantitative release of hydrophobic naproxen by generating high porosity and thereby expanding polymer/water interface.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1991년도 추계학술대회
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• pp.96-97
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• 1991

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.302-302
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• 2006

Nanoaggregates of triple hydrophilic block copolymers comprised of poly(ethylene oxide), poly(sodium 2-acrylamido)-2-methylpropanesulfonate), and poly(methacrylic acid) (PEO-PAMPS-PMAA) and the cationic surfactant, dodecyltrimethylammonium chloride (DTAC) have been fabricated. The formation of $^{\circ}^{\circ}$the nanoaggregates is based on electrostatic interaction of sulfonate and carboxylate groups of PAMPS and PMAA blocks with the cationic surfactant, which results in insolubilization of these blocks. The formation of micelle is observed by dynamic light scattering measurements. Binding of DTAC to the anionic blocks of PEO-PAMPS-PMAA is confirmed by electrophoresis measurements.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.85-85
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• 2006

The micellization behavior and the metal-nanoparticle formation in PDEAEMA-b-PHEGMA double hydrophilic block copolymers are investigated. The hydrophobic PDEAEMA block is pH-sensitive: at low pH it can be protonated and it becomes hydrophilic, leading to molecular solubility, whereas at higher pH micelles are formed; the behavior is studied by DLS, NMR and AFM. In these micellar nanoreactors, metal nanorystals nucleate and grow upon reduction with sizes in the range of a few nm's as observed by TEM and XRD. Similarly, metal nanocrystals can be formed within pH-sensitive microgels (${\sim}250nm$ in diameter), synthesized by emulsion copolymerization of DEAEMA, which also exhibit reversible swelling properties in water by adjusting the pH.

• Nuclear Engineering and Technology
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• 제6권3호
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• pp.161-169
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• 1974

Nylon직포의 표면을 친수화 하기 위하여 동시조사법으로 Acrylic acid를 방사선 graft중합시켰다. Monomer용액속서 침지된 Nylon직포를 공기중 또는 진공하에서 ${\gamma}$-선으로 조사시켰다. 직포 표면에 형성된 Polyacrylic acid는 10$0^{\circ}C$의 sodium hydroxide용액(0.1%)으로 대부분 추출되었다. 접목 반응된 생성물의 화학적 조성을 측정하였다. 접목반응된 Polymer와 방사선 처리를 하지 않은 polyamide를 비교하여 볼 때 흡수성이라든가 대전성은 증진되었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1296-1301
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• 2003

The chemical mechanical polishing(CMP) is necessarily applied to manufacturing the dielectric layer and metal line in the semiconductor device. The conditioning of polishing pad in CMP process additionally operates for maintaining the removal rate, within wafer non-uniformity, and wafer to wafer non-uniformity. But the fixed abrasive pad(FAP) using the hydrophilic polymer with abrasive that has the swelling characteristic by water owns the self-conditioning advantage as compared with the general CMP. FAP also takes advantage of planarity, resulting from decreasing pattern selectivity and defects such as dishing due to the reduction of abrasive concentration. This paper introduces the manufacturing technique of FAP. And the tungsten CMP using FAP achieved the good conclusion in point of the removal rate, non-uniformity, surface roughness, material selectivity, micro-scratch free contemporary with the pad life-time.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.103-104
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• 2007

Nanometer-scaled polymer beads, such as polystyrene beads, were used as nanometer fabrication materials due to their some advantages such as self-assembled monolayer, nanometer scaled size and excellent compatibility with silicon based devices. Thus, the investigation on these properties of polymer beads was required. It is difficult to control the array of polystyrene beads on silicon substrate. In this study, we investigated the condition of selective array of polystyrene beads on nanometer-scaled hydrophilic surface which was obtained by APS coating. A tilting method was used to array the polystyrene beads selectively on the substrate. The polystyrene beads could be arrayed selectively by this method. From these results, we verified that there are possibilities to fabricate unique tools for the nanometer-scaled electrical devices.

• 한국염색가공학회지
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• 제4권4호
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• pp.110-116
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• 1992

For the modification of PET surface, Perfluoropropene and Methyl alcohol were LT-plasma polymerized on the PET fabrics as thin films by means of 13.56 MHz radio frequency generator. The surface properties of PET fabrics were modified from hydrophobic to hydrophilic by application of the postplasma reaction of thin films. The evidence of the modification was identified by observation of the presence of hydroxy group in IR spectrum and the evaluation of degree of hydrophilicity was performed by measuring frictional static voltage of PET fabric with cotton fabric. For the case of modification by PFP, the result performed at the condition of 25 W, 70 m torr has shown to be effective, and for MeOH, result performed at the condition of 25 W, 100 m torr effective. The effect of hydrophilic surface modification of MeOH plasma polymer was superior to that of PFP-plasma polymer.

• Bulletin of the Korean Chemical Society
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• 제30권11호
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• pp.2589-2594
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• 2009

Aging phenomena of plasma polymer films were studied by using the surface analysis techniques of contact angle measurement, X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (TOFSIMS), and atomic force microscopy (AFM). The polymer films were grown on an aluminum substrate by using a plasma polymerization method from a gas mixture of acetylene and helium, and the films were subsequently modified to have a hydrophilic surface by oxygen plasma treatment. Aging of the polymer films was examined by exposing the samples to water and air environments. The aging process increased the hydrophobicity of the surface, as revealed by an increase in the advancing contact angle of water. XPS analysis showed that the population of oxygen-containing polar groups increased due to the uptake of oxygen during the aging, whereas TOF-SIMS analysis revealed a decrease in the polar group population in the uppermost surface layer. The results suggest that the change in surface property from hydrophilic to hydrophobic nature results from the restructuring of polymer chains near the surface, rather than compositional change of the surface. Oxidative degradation may enhance the mobility and the restructuring process of polymer chains.