• Proceedings of the Membrane Society of Korea Conference
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• 2004.05b
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• pp.1-8
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• 2004

Ion-conducting polymer electrolyte membranes (PEMs) have recently used in developing fuel cell or solar cell for portable, mobile and residential applications [1]. Polymer electrolyte membrane fuel cell (PEMFC), direct methanol fuel cell (DMFC), alkaline electrolyte fuel cell (AFC) and dye-sensitized solar cell have been employing the ion-conducting PEMs to complete their electrical circuits to produce electricity.(omitted)

• Proceedings of the Membrane Society of Korea Conference
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• 2001.11a
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• pp.115-118
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• 2001

• Membrane Journal
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• v.27 no.5
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• pp.434-440
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• 2017

Electrical impedance spectroscopy is used to detect membrane fouling in-situ in reverse electrodialysis. The impedance data for the AMX membrane being fouled in the reverse electrodialysis are plotted and analyzed by Nyquist and admittance method. The meaningful graphical analyses for the fouling phenomena could be done by both Nyquist and admittance method. In addition, the unstable initial fouling stage was identified by the admittance data with high standard deviation, and the structural change of the fouling layer formed at the surface of anion-exchange membranes with the operation time of reverse electrodialysis was also detected.

• Membrane Journal
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• v.32 no.6
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• pp.442-455
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• 2022

High-temperature polymer electrolyte membrane fuel cell (HT-PEMFC) has been studied as an alternative to low-temperature PEMFC due to its fast activation of electrodes and high resistance to electrode poisoning by carbon monoxide. It is highly required to develop stable PEMs operating at high temperatures even doped by ion-conducting materials for the development of high-performance and durable HT-PEMFC systems. A number of studies have been conducted to develop polybenzimidazole (PBI)-based PEMs for applications in HT-PEMFC due to their high interaction with doped ion-conducting materials and outstanding thermomechanical stability under high-temperature operation. This review focused on the development of PBI-based PEMs showing high performance and durability. Firstly, the characteristic behavior of PBI-based PEMs doped with various ion-conducting materials including phosphoric acid was systematically investigated. And then, a comparison of the physicochemical properties of the PEMs according to the different membrane manufacturing processes was conducted. Secondly, the incorporation of porous polytetrafluoroethylene substrate and/or inorganic composites to PBI matrix to improve the membrane performances was studied. Finally, the construction of cross-linked structures into PBI-based PEM systems by polymer blending method was introduced to improve the PEM properties.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.129.2-129.2
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• 2010

AEM which were used for solid alkaline fuel cell(SAFC) were prepared by photo polymerization in method pore-filling with various quaternary ammonium cationic monomers and crosslinkers without an amination process. Their specific thermal and chemical properties were characterized through various analyses and the physico-chemical properties of the prepared electrolyte membranes such as swelling behavior, ion exchange capacity and ionic conductivity were also investigated in correlation with the electrolyte composition. The polymer electrolyte membranes prepared in this study have a very wide hydroxyl ion conductivity range of 0.01 - 0.45S/cm depending on the composition ratio of the electrolyte monomer and crosslinking agent used for polymerization. However, the hydroxyl ion conductivity of the membranes was relatively higher at the whole cases than those of commercial products such as A201 membrane of Tokuyama. These pore-filling membranes have also excellent properties such as smaller dimensional affects when swollen in solvents, higher mechanical strength, lowest electrolyte crossover through the membranes, and easier preparation process compared of traditional cast membranes. The prepared membranes were then applied to solid alkaline fuel cell and it was found comparable fuel cell performance to A201 membrane of Tokuyama.

• Journal of Hydrogen and New Energy
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• v.28 no.2
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• pp.144-149
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• 2017

A proton-conducting bisphenylpropaned sulfonated fluorinated blockcopolymer (BPSFBC) was synthesized. Five kinds of polymer electrolyted composite membranes were preparated by incorporating silica ($SiO_2$) with various weight ratio. And their characteristics were investigated by FT-IR (fourier transform infrared), $^1H-NMR$ ($^1H$ nuclear magnetic resonance), TGA (thermogravimetric analysis), water uptake, FE-SEM (field emission scanning electron microscopes), and ion conductivity properties. The water uptake and ion conductivity were increased until 9 wt% $SiO_2$, and then decreased. The maximum proton conductivity equal to $52mScm^{-1}$ was measured for the BPSFBC/$SiO_2$-9 composite membrane at $90^{\circ}C$ and 100% relative humidity. From the measured results, it is distinct that the manufactured composite membrane BPSFBC/$SiO_2$-9 can be considered as a polymer membrane suitable for a fuel cell electrolyte.

• Journal of Electrochemical Science and Technology
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• v.9 no.3
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• pp.212-219
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• 2018

Perovskite type ceramic membranes which exhibit dual ion conduction (proton and oxygen ion conduction) can permeate water and can aid solving operational problems such as temperature gradient and carbon deposition associated with a working solid oxide fuel cell. From this point of view, it is crucial to reveal water transport mechanism and especially the nature of the surface sites that is necessary for water incorporation and evolution. $BaCe_{0.8}Y_{0.2}O_{3-{\alpha}}$ (BCY20) was used as a model proton and oxygen ion conducting membrane in this work. Four different catalytically modified membrane configurations were used for the investigations and water flux was measured as a function of temperature. In addition, CO was introduced to the permeate side in order to test the stability of membrane against water and $CO/CO_2$ and post operation analysis of used membranes were carried out. The results revealed that water incorporation occurs on any exposed electrolyte surface. However, the magnitude of water permeation changes depending on which membrane surface is catalytically modified. The platinum increases the water flux on the feed side whilst it decreases the flux on the permeate side. Water flux measurements suggest that platinum can block water permeation on the permeate side by reducing the access to the lattice oxygen in the surface layer.

• Applied Chemistry for Engineering
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• v.24 no.4
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• pp.337-343
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• 2013

Membrane reactors have been showing a promising future and attracted increasing attention in the scientific community as they possess advantages in terms of enhanced catalytic activity and selectivity, combination of processes (reaction and separation), simplicity in process design, and safety in operation. In particular, solid electrolyte membrane reactor principles are realized in fuel cells, electrolyzers and reactors for hydrogenation of carbon dioxide and other economically viable reactions. In this review, as a young generation of ion conducting materials, high temperature proton conductors are discussed in terms of the current status of material development and their various applications.

• Journal of the Korean Applied Science and Technology
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• v.30 no.2
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• pp.258-263
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• 2013

New conducting polymers containing heterocyclic ring with carbazole, EDOT and benzobisthiazole were synthesized and characterized by organic spectroscopic methods. Potentiometric ion-selective membrane electrodes (ISMEs) have been extensively used for ion analysis in clinical, environmental, and industeial fields owing to its wide response range (4 to 7 orders of magnitude), no effect of sample turbidity, fast response time, and ease of miniaturization. Considerable attention has been given to alternative use of room temperature vulcanizing (RTV)-type silicone rubber(SR) owing to its strong adhesion and high thermal durability. Unfortunately, the high membrane resistance of SR-based (ISMs)(2 to 3 higher orders of magnitude compared to those of poly(vinyl chloride)(PVC)-based ones) has significantly restricted its application. Herein we demonstrate a new method to reduce membrane resistance via addition of new conducting polymer into the SR-based ISMs.

• Membrane Journal
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• v.27 no.5
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• pp.425-433
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• 2017

As the problems related to the environmental pollution such as carbon dioxide emission are emerging, the need for the renewable energy and environmentally friendly energy is getting intense. Fuel cells are eco-friendly energy generation devices that generate electrical energy and produce water as a sole by-product. Compared to the traditional proton exchange membrane fuel cell (PEMFC), anion exchange membrane alkaline fuel cell (AEMAFC) has a main advantage of possibility to use low cost metal catalysts due to its faster kinetics. The AEM, which conducts $OH^-$ ions, should possess high ion conductivity as well as high chemical stability at high pH conditions. We hereby introduce a crosslinked poly(2,6-dimethyl-1,4-phenylene oxide) having a spacer-type conducting group as novel AEM, and report a high ion conductivity ($67.9mScm^{-1}$ at $80^{\circ}C$) and mechanical properties (Young's modulus : 0.53 GPa) as well as chemical stability (6.8% IEC loss at $80^{\circ}C$ for 1,000 h,) for the developed membrane.