• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.369-372
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• 2004

Orientation of E7 liquid crystals(LCs) confined to 200 nm-diameter cylindrical cavities of Anodisc membranes are investigated by FTIR dichroism techniques. The cavity walls of the confining pores are chemically modified with different perfluorinated carboxylic acids (PCA, $C_nF_{2n+1}$COOH, n=3, 4, 5, 6). From the FTIR spectra of PCA treated alumina Anodsic membranes, we found the salt formation between -COOH group of PCA and Anodisc membrane. From the FTIR spectra of LC filled Anodisc membranes, we found abrupt alignment direction change of LC molecules between n=4 and 5 for 1 mM PCA treated Anodisc membranes, from parallel to perpendicular direction to the cavity walls. But 5mM PCA treated Anodisc membranes, alignment direction of LC molecules changed between n=3 and n=4, from parallel to perpendicular direction.

• 멤브레인
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• 제30권6호
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• pp.395-408
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• 2020

고분자 전해질 막 연료전지(polymer electrolyte membrane fuel cell, PEMFC)는 환경오염물질 배출이 없는 친환경 에너지 변환 장치로 주목을 받고 있다. PEMFC의 구성요소 중 고분자 전해질 막(polymer electrolyte membrane, PEM)은 음극에서 발생되는 수소이온을 양극으로 전달하는 역할과 동시에 분리막으로써 연료의 투과를 차단하는 역할을 수행하는 핵심 소재이다. 대표적으로 Nafion®과 같은 과불소화계 고분자 전해질 막이 상용화 되어있지만 높은 단가 및 분해 시 환경오염물질이 배출되는 단점이 존재하여, 이를 대체할 탄화수소계 고분자를 활용한 전해질 막 개발에 관한 연구들이 수행되고 있다. 높은 수소이온 전도도를 가지며 동시에 우수한 물리·화학적 안정성을 갖는 탄화수소계 고분자 기반 전해질 막을 개발하기 위해 가교 구조가 도입된 전해질 막을 개발하는 연구들이 보고되고 있다. 본 총설은 가교 전해질 막을 제조하기 위해 이온교환 작용기가 도입된 탄화수소계 고분자를 활용하여 다양한 종류의 가교 전해질 막을 제조하는 방법에 대해 논하였다.

• Macromolecular Research
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• 제17권3호
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• pp.187-191
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• 2009

Platinum (Pt) nanoparticles were prepared by the liquid-phase reduction of tetraammineplatinum (II) chloride $([Pt(NH_3)_4]Cl_2)$ using Nafion as a stabilizer under various conditions of the Nation phase. This method is novel in its use of electrostatic interactions between the Pt complex ions and sulfonic groups in the hydrated Nation molecules. The synthesized Pt nanoparticles of the recast film system had a cubic shape. In the case of the Nation solution system, the Pt nanoparticles mainly had a spherical shape. The shapes and sizes of the Pt nanoparticles were strongly influenced by the Nation phase.

• 대한화학회지
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• 제47권2호
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• pp.115-120
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• 2003

Perfluorinated sulfonated polymer(Nafion)-ethylenediamine(en)이 화학수식된 유리탄소전극으로 Fe(II) 이온의 정량에 대해 연구하였다. Fe(II) 이온의 착화제인 en을 nafion에 고정시켜 유리탄소전극 표면에 수식하면 이 수식전극의 en은 Fe(II) 이온과 $[Fe(en)_3]^{+2}$의 착물을 형성한다. Nafion-en이 화학수식된 유리탄소전극에서 시차펄스전압전류법에 의한 Fe(II) 이온의 산화봉우리전위는 0.340${\pm}$0.015 V(vs. Ag/AgCl), 측정범위는 $5{\times}10^{-6}{\sim}0.2{\times}10^{-3} M(0.28{\sim}11.17 mg/L)$, 검출한계(3s)는 $1.89{\times}10^{-5}$M(1.056 mg/L)이었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1813-1818
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• 2006

We demonstrate a new approach to form gradient hole injection layer (HIL) in organic light-emitting diodes (OLEDs). Single spincoating of hole-injecting conducting polymer compositions with a perfluorinated ionomer results in gradient workfunction through the layer by self-organization, which lead to remarkably efficient single layer polymer light-emitting diodes (PLEDs) (${\sim}21$ cd/A). The device lifetime was significantly improved (${\sim50$ times) compared with the conventional hole injection layer, poly(3,4-ethylenedioxy-thiophene)/polystyrene sulfonate. This solution processed HIL also produced dramatically enhanced luminous efficiency (${\sim}34$ cd/A) in vacuum- deposited green fluorescent OLEDs while the vacuum deposited HIL gave the luminous efficiency of ${\sim}23$ cd/A in the same device structure.

• 멤브레인
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• 제2권1호
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• pp.49-58
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• 1992

Functionalized organic polymers have been used as supports for heterogenized homogeneous catalytic process[1]. Sprcific advantages of using these resins as support reagents have been reviewed[2-4]. These include: -ease of by-product separation from the main reaction product usuallyby simple filtration. -prevention of intermolecular reaction of reactive species or functional groups by simulating high dilution conditions[5]. -utility of the "fish-hook" principle in which a minor component in fished out of a large excess substrate by the insoluble polymer[6]. -the possibility of reusing recovered reagents as well as eliminating the use of volatile or noxious substances[7]. Catalysis by ion-exchange membranes is perhaps one of the latest examples of the use of a polymer-supported species. Conceptually, catalysts on membrane supports offer several possible advantages over traditional powder type systems. They are: (1) Membranes immobilize the catalyst, preventing agglomeration. (2) Filtration is unnecessary for the catalyst separation and so complete catalyst recovery is facilitated. (3) Catalytyic and separation processes can be combined, allowing membrane supported catalysts for the continous flow reactors. reactors.

• 멤브레인
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• 제27권5호
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• pp.389-398
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• 2017

연료전지용 고분자 전해질막에 있어서 가장 중요한 특성인 수소이온 전달 능력은 내부에서 형성되는 수화채널의 분포 및 형상에 큰 영향을 받게 된다. 비과불화탄소계인 탄화수소계 전해질막의 경우, 과불화탄소계 전해질막인 나피온에 비하여 이러한 수화채널이 약하게 형성되는 것으로 알려져 있으며 따라서 상대적으로 낮은 이온전달 성능을 나타내는 것으로 보고되고 있다. 본 연구에서는 컴퓨터를 이용한 전산모사 기술의 하나인 메조스케일 전산모사 기술을 이용하여 탄화수소계 연료전지용 전해질막인 술폰화 폴리이미드의 가습조건에서의 수화채널 형성 및 상분리 현상을 관찰하였다. 이를 통하여 술폰화 폴리이미드 내부에서 물분자 비드는 친수성 영역 전체에 걸쳐서 고르게 분포되며 명확한 수화 클러스터는 높은 술폰화도에서만 형성되는 것이 관찰되었다. 또한, 술폰화 폴리이미드 모델은 저가습 상태에서 수화 채널을 형성하는데에 나피온 모델에 비하여 더 어렵다는 것이 관찰되었다. 이러한 결과들은 비과불화불소계인 탄화수소계 전해질막의 수화채널 형성에 대한 기존 이론을 명확하게 뒷받침하고 있으며, 술폰화 폴리이미드의 전도도 경향도 잘 설명을 하고 있다. 따라서 메조스케일 전산 모사 기술은 연료전지용 전해질막의 상분리 현상 및 수화채널을 분석하고 이온전도 특성을 규명하는 데에 있어서 매우 효과적인 기술이 될 수 있다는 것을 확인하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.75.2-75.2
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• 2010

Polymer electrolyte fuel cells (PEFCs) have received a lot of attention as a power source for both stationary and mobile applications due to their attractive feature. In general, the performance of PEFCs is highly affected by the property of the electrodes. A PEFC electrode essentially consists of a gas diffusion layer and a catalyst layer. The gas difusion layer is highly porous and hydrophobicized with PTFE polymer. The catalyst layer usually contains electrocatalyst, proton conducting polymer, even PTFE as additive. Particularly, the proton conducting ionomer helps to increase the catalytic activity at three-phase boundary and catalyst utilization. Futhermore, it helps to retain moisture, resulting in preventing the electrodes from membrane dehydration. The most widely used proton conducting ionomer is perfluorinated sulfonic acid polymer, namely, Nafion from DuPont due to its high proton conductivity and good mechanical property. However, there are great demands for alternative ionomers based on non-fluorinated materials in terms of high temperature availability, environmental adaptability and production cost. In this study, the electrodes with the various content of the sulfonated poly(ether sulfone) ionomer in the catalyst layer were prepared. In addition, we evaluated electrochemical properties of the prepared electrodes containing the various amount of the ionomers by using the cyclic voltammetry and impedance spectroscopy to find an optimal ionomer composition in the catalyst layer.

• 한국막학회:학술대회논문집
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• 한국막학회 1999년도 The 7th Summer Workshop of the Membrane Society of Korea
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• pp.115-115
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• 1999

In this work a new process was developed for the sulfonation of the chemicallly stable engineering polymer polyethersulfone as membrane materials for electrodialysis or a flow battery applications. Commercially available polyethersulfone polymer was partially sulfonated using a CSA sulfonating agent in a dichloromethane solvent, which sulfonated polyethersulfone with various sulfonation levels have been prepared. Sulfonated polyethersulfone (SPES) membranes with different ion capacities were prepared for the purpose of identifying cation exchange membrane properties, in an attempt to find a low cost replacement for Nafion, which most of the perfluorinated membranes, known to exhibit a prolonged service life, are expensive and difficult to process. The following features were determined: the degree of sulfonation, water uptake, thermal analysis, and electrochemical properties such as ion exchange capacities, resistivity, selectivity of ion permeation. The surface of the cation exchange membranes, decomposed with the H202-treatment, were observed by using scanning electron microscope. The area resistivities of SPES mebranes in 5N-NaOH decreased from $2,150{\;}{\Omega}-cm2$ to less than $15{\Omega}-cm2$ as the ion exchange capacity (IEC) increased from 0.62 to 1.73 millieequivlants per dry gram(meq/dg).eq/dg).

• 통합자연과학논문집
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• 제7권3호
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• pp.188-192
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• 2014

Determination of cobalt(III) ion with a perfluorinated sulfonated polymer-ethylenediamine (nafion-en) modified glassy carbon electrode is studied. It is based on the chemical reactivity of an immobilized layer, nafion-en, to yield complex $[Co(en)_3]^{3+}$. The reduction peak potential by differential pulse voltammetry (DPV) is observed at $-0.437{\pm}0.047$ V (vs. Ag/AgCl). The linear calibration curve is obtained in cobalt(III) ion concentration range $1.0{\times}10^{-8}{\sim}1.0{\times}10^{-3}M$ ($5.893{\times}10^{-12}{\sim}5.893{\times}10^{-5}g/mL$).