• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.265-265
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• 2006

Multivalent interactions, which are characterized by the simultaneous binding of multiple ligands on multiple receptors, are prevalent in biological system. We have shown that it is able to make a supramolecular aggregate coated with multiple functional molecules fairly easily by simply mixing one building block. In this particular example, a mannose-coated object was able to agglutinate bacterial cells with cognate binding partners through multivalent interactions. This kind of strategy can be applied in developing materials that can selectively remove pathogens. Supramolecular assembly of this type should be very useful in exploring multivalent biological interactions.

• Macromolecular Research
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• 제15권4호
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• pp.343-347
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• 2007

Novel composite membranes, which delivered high separation performance for propylene/propane mixtures, were developed by coating inert poly(ethylene-co-propylene) rubber (EPR) onto a porous polyester substrate, followed by the physical distribution of $AgBF_4$. Scanning electron microscopy-wavelength dispersive spectrometer (SEM-WDS) revealed that silver salts were uniformly distributed in the EPR layer. The physical dispersion of the silver salts in the inert polymer matrix, without specific interaction, was characterized by FT-IR and FT-Raman spectroscopy. The high separation performance was presumed to stem from the in-situ dissolution of crystalline silver ionic aggregates into free silver ions, which acted as an active propylene carrier within a propylene environment, leading to facilitated propylene transport through the membranes. The membranes were functional at all silver loading levels, exhibiting an unusually low threshold carrier concentration (less than 0.06 of silver weight fraction). The separation properties of these membranes, i.e. the mixed gas selectivity of propylene/propane ${\sim}55$ and mixed gas permeance ${\sim}7$ GPU, were stable for several days.

• 폴리머
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• 제31권6호
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• pp.512-517
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• 2007

[ $Co_{60}\;{\gamma}-ray$ ] 방사선 조사법을 이용하여 kapok 섬유에 styrene, glycidylmethacrylate(GMA) 또는 acrylic acid(AAc)를 그래프트 공중합 반응하여 합성한 공중합체의 그래프트율은 단량체의 농도와 방사선 조사량에 따라 증가하는 것으로 나타났으며, 또한 합성된 이온교환 섬유의 도입된 관능기를 확인하고 이온교환 능을 측정하였으며, SEM과 FT-IR을 통하여 이온교환 섬유의 표면과 구조를 분석하였다.

• 폴리머
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• 제33권5호
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• pp.413-419
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• 2009

프리즘 시트의 프리즘 층 물질의 굴절률을 증가시킬수록 휘도가 향상되어 LCD 백라이트 유닛의 효율이 향상되었다. 프리즘 층의 굴절률을 증가시키기 위해서 방향족을 포함하고 있는 고굴절 물질과 다관능성 반응물을 혼합하여 자외선 경화형 수지를 제조하였다. 9,9-Bis [4-(2-acryloyloxyethoxy)phenyl] fluorene을 반응시켜 프리즘층의 도막 굴절률을 1.58까지 증가시켰고 백라이트의 휘도를 향상시킬 수 있었다. 백라이트 유닛에 사용되는 광원에 장기간 노출될 경우 프리즘 시트에 황변현상이 발생하게 되어 휘도가 감소되므로 자외선 안정제로 hindered amine light stabilizer를 사용하여 프리즘 시트의 내황변성을 크게 향상시켰다.

• 한국막학회:학술대회논문집
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• 한국막학회 1997년도 추계 총회 및 학술발표회
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• pp.83-84
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• 1997

1. INTRODUCTION : Polyimides containing siloxane moiety(poly(imide siloxane), or polysiloxaneimide) have been synthesized because of their some merits over polyimide itseft. Polyimides have excellent thermal and mechanical properties but their poor solubility and processibility in their fullly imidized form give disadvantages in applications. Incorporation of siloxane units make it possible to increase solubility and processibility, and also impart impact resistance, low moisture uptake, low dielectric constant, thermo-oxidative resistance, good adhesion properties to substrate and etc.. Incorporation methods of siloxane groups into the polyimide was mainly copolymerization or terpolymerization between oligomeric dimethylsiloxane and aromatic dianhydride. A few methods of introducing siloxane units in functional groups of polyimide was reported. In our laboratory poly(amideimide siloxane) and poly(imide siloxane) were prepared and the study about their thermal kinetics was performed. In separation membrane area, polysiloxaneimides was utilized in pervaporation and gas separation. Polyimides in gas separation show high selectivity and very low permeability, and introduction of siloxane segments increase permeability with low decrease in selectivity. We aimed to introduce silicone segments into poly(amic acid) state and synthesize polymer partially imidized, and also show the gas separation characteristics of the synthesized polymer.

• 멤브레인
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• 제26권1호
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• pp.38-42
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• 2016

올레핀/파라핀 혼합 기체의 분리를 위한 올레핀 촉진 수송 분리막의 제조를 위해 amide 작용기를 가지며 glassy한 특성을 보이는 polyvinylpyrrolidone (PVP) 고분자를 분리막의 matrix로서 사용하였다. 분리막의 기체 투과 실험은 propylene과 propane 50 : 50의 부피비로 혼합된 기체를 사용하였고, bubble meter와 gas chromatography를 사용해 투과도와 선택도를 측정하였다. 또한 SEM image와 FT-IR을 통해 막의 특성을 조사하였다. 100시간의 장시간 성능 측정 결과 선택도는 약 15, 투과도는 약 1.3 GPU 이상을 각각 유지하였다. 기존의 poly(2-ethyl-2-oxazoline) $(POZ)/AgBF_4/Al(NO_3)_3$ 분리막과 비교함으로써, 고분자 matrix로서의 PVP 특성을 확인하였다.

• Carbon letters
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• 제28권
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• pp.60-65
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• 2018

Linear carbon chains (LCCs) encapsulated inside the hollow cores of carbon nanotubes (CNTs) have been experimentally synthesized and structurally characterized by Raman spectroscopy and transmission electron microscopy. However, in terms of electronic conductivity, their transportation mechanism has not been investigated theoretically or experimentally. In this study, the density of states and quantum conductance spectra were simulated through density functional theory combined with the non-equilibrium Green function method. The encapsulated LCCs inside (5,5), (6,4), and (9,0) single-walled carbon nanotubes (SWCNTs) exhibited a drastic change from metallic to semiconducting or from semiconducting to metallic due to the strong charge transfer between them. On the other hand, the electronic change in the conductance value of LCCs encapsulated inside the (7,4) SWCNT were in good agreement with the superposition of the individual SWCNTs and the isolated LCCs owing to the weak charge transfer.

• 한국전기전자재료학회논문지
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• 제30권10호
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• pp.665-671
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• 2017

Herein, we report the fabrication of low-voltage N-type organic field-effect transistors by using high capacitance fluorinated polymer gate dielectrics such as P(VDF-TrFE), P(VDF-TrFE-CTFE), and P(VDF-TrFE-CFE). Electron-withdrawing functional groups in PVDF-based polymers typically cause the depletion of negative charge carriers and a high contact resistance in N-channel organic semiconductors. Therefore, we incorporated intermediate layers of a low-k polymerto prevent the formation of a direct interface between PVDF-based gate insulators and the semiconducting active layer. Consequently, electron depletion is inhibited, and the high charge resistance between the semiconductor and source/drain electrodes is remarkably improved by the in corporation of solution-processed charge injection layers.

• 접착 및 계면
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• 제21권3호
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• pp.113-122
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• 2020

중간 세공체(mesoporous) 물질은 높은 표면적과 조절 가능한 기공 크기를 가진 규칙적인 다공성 구조로 최근 다양한 응용분야를 가진 매력적인 재료로 알려져 있다. 중간 세공체 물질 중 특히 유/무기 하이브리드형 실리카 나노세공체(Periodic Mesoporous Organosilica; PMO)는 세공의 크기가 확대되고 골격에 유기물을 도입함으로써 더욱 다양한 응용분야를 확보할 수 있는 새로운 재료로 큰 주목을 받고 있다. 골격 구조에 유기 그룹을 도입하게 되면 표면 물성과 재료 전체 물성의 제어가 가능하게 된다. 본 총설은 PMO의 합성, 기능성, 모폴로지는 물론이고 촉매나 환경분야 응용 등을 포함한 내용을 개괄적으로 고찰하였으므로, PMO의 주요 기능과 응용성에 대한 이해를 높이는데 기여할 것이다.

• Macromolecular Research
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• 제11권3호
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• pp.163-171
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• 2003

For the pervaporation of water-ethanol mixtures, new composite membranes having poly(acrylic acid)-poly (butyl methacrylate-co-methyl methacrylate) interpenetrati ng polymer network [PAA-P(BMA-co-MMA) IPN] skin layer supported on porous and crosslinked poly(BMA-co-MMA) were prepared. The morphology of the sub-layer of the composite membrane prepared in the presence of 60 wt% solvent showed cellular structure, on the other hand that of sublayer prepared in the presence of 70 wt% solvent presented very porous interconnected pore structure with macrovoids. Permeation rates of the composite membranes were largely influenced by the morphology of the sublayer. Separation factors increased with the increase of the degree of crosslinking of the PAA network. It was found that permeation rates could be increased by introducing anionic charges on carboxyl groups of the PAA. The permeation rate changes of the PAA-P(BMA-co-MMA) IPN composite membranes according to the feed compositions showed quite similar pattern with the swelling behavior in water-ethanol mixtures.